Energy storage devices and energy storage systems

Abstract

An energy storage device (10) and an energy storage system (100) are provided. The energy storage device (10) is used to electrically connect to an energy storage converter (20). The energy storage converter (20) can be used to cooperate with M energy storage devices (10). The rated output power of the energy storage converter (20) is P, the energy of the energy storage device (10) is Q, and the time for the energy storage device (10) to discharge from a fully charged state to a fully discharged state is A, satisfying: 0.7≤P / (M*Q / A)≤0.99. P / (M*Q / A)≤0.99 ensures that the power of all energy storage devices (10) cooperating with the energy storage converter (20) has sufficient margin compared with the power of the energy storage converter (20), and no capacity supplementation is required for the energy storage device (10) over a long period of time, thus achieving long-term reliability of the energy storage device (10). The power ratio P / (M*Q / A)≥0.7 ensures that the power of the energy storage device (10) is not excessively large compared to the power of the energy storage converter (20), reducing power waste and improving the economy of the energy storage device (10). This improves the power matching between the energy storage device (10) and the energy storage converter (20).

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to international application (PCT / CN2023 / 101942) entitled “Energy Storage Device and Energy Storage System”, filed on June 21, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of energy storage technology, and more specifically, to an energy storage device and an energy storage system. Background Technology

[0004] Energy storage devices are electrical energy storage and transfer equipment. They can be used in power systems to store surplus electricity during off-peak hours to supplement peak demand. Therefore, energy storage devices can both store excess power generated by the power generation system and supply power to the grid when the power generation system generates less electricity.

[0005] Energy storage devices typically consist of a casing and multiple battery cells housed within it. These cells can be connected in series, parallel, or a combination of multiple cells to store electrical energy. Energy storage devices generally require connection to an energy storage converter to enable charging and discharging. Currently, the power matching between energy storage devices and energy storage converters is relatively poor. Summary of the Invention

[0006] This application provides an energy storage device and an energy storage system that can effectively improve the power matching between the energy storage device and the energy storage converter.

[0007] In a first aspect, embodiments of this application provide an energy storage device for electrically connecting an energy storage converter. The energy storage converter can be used to cooperate with M energy storage devices, where M is a positive integer. The rated output power of the energy storage converter is P (in W), the energy of the energy storage device is Q (in Wh), and the time for the energy storage device to discharge from a fully charged state to a fully discharged state is A (in h), satisfying: 0.7≤P / (M*Q / A)≤0.99.

[0008] In the above technical solution, P / (M*Q / A)≤0.99 ensures that the power of all energy storage devices working with the energy storage converter has sufficient margin compared to the power of the energy storage converter, eliminating the need for capacity expansion of the energy storage devices over a long period and achieving long-term reliability. P / (M*Q / A)≥0.7 ensures that the margin between the power of the energy storage devices and the power of the energy storage converter is not excessive, reducing power waste and improving the economic efficiency of the energy storage devices. Thus, from the perspective of long-term reliability and economy, the power matching between the energy storage devices and the energy storage converter is improved.

[0009] In some embodiments, 0.75 ≤ P / (M*Q / A) ≤ 0.95. This approach balances the long-term reliability and economy of energy storage devices, keeping costs low while allowing for longer capacity replenishment cycles.

[0010] In some embodiments, 0.85 ≤ P / (M*Q / A) ≤ 0.93.

[0011] In some embodiments, the energy storage device includes a housing and at least one battery. The housing includes a battery compartment, in which at least one battery is housed. The battery includes at least one individual battery cell. The capacity of the individual battery cell is C (Ah), the plateau voltage of the individual battery cell is U0 (V), and the total number of individual battery cells in the battery compartment is N, where Q = N * C * U0. This ensures that all individual battery cells in the battery compartment have the same capacity, allowing the selection of battery cells of the same specification. On the one hand, this improves the assembly efficiency of the energy storage device; on the other hand, it reduces the probability of wasted space due to different specifications of individual battery cells in the battery compartment.

[0012] In some embodiments, the battery compartment contains N1 batteries, which are formed by X1 first battery packs connected in parallel, each first battery pack being formed by Y1 batteries connected in series; or, the N1 batteries are formed by Y1 second battery packs connected in series, each second battery pack being formed by X1 batteries connected in parallel, satisfying: N1≥1, X1≥1, Y1≥1, N1=X1*Y1; the battery includes N2 battery cells, which are formed by X2 first battery cell groups connected in parallel, each first battery cell group being formed by Y2 battery cells connected in series; or, the N2 battery cells are formed by Y2 second battery cell groups connected in series, each second battery cell group being formed by X2 battery cells connected in parallel, satisfying: N2≥1, X2≥1, Y2≥1, N2=X2*Y2, N=N1*N2. For the N1 batteries in the battery compartment, Y1 batteries can be connected in series to form a first battery pack, and then X1 first battery packs can be connected in parallel; alternatively, X1 batteries can be connected in parallel to form a second battery pack, and then Y1 second battery packs can be connected in series. For the N2 individual battery cells, Y2 individual battery cells can be connected in series to form a first battery cell group, and then X2 first battery cell groups can be connected in parallel; alternatively, X2 individual battery cells can be connected in parallel to form a second battery cell group, and then Y2 second battery cell groups can be connected in series. The number of batteries connected in series Y1 and the number of individual battery cells connected in series Y2 in the battery compartment can be set according to requirements to adjust the voltage of the energy storage device to a reasonable range.

[0013] In some embodiments, when the energy storage device is being charged, the maximum operating voltage on the DC side of the energy storage converter is U1, and the minimum operating voltage on the DC side of the energy storage converter is U2, satisfying: U2 < U0 * Y1 * Y2 < U1. This ensures that the voltage of the energy storage converter is matched with the voltage of the energy storage converter, enabling both external devices to charge the energy storage device through the energy storage converter and the energy storage device to supply power to external devices through the energy storage converter.

[0014] In some embodiments, the positive electrode material of the battery cell includes lithium phosphate, with a voltage of 2.8V ≤ U0 ≤ 3.6V and 250 ≤ Y1*Y2 ≤ 468. Thus, when the positive electrode material of the battery cell includes lithium phosphate, the voltage of the energy storage converter can be controlled within a reasonable range. This ensures that the voltage of the energy storage device is not too low, allowing it to be compatible with energy storage converters with higher operating voltages, while also preventing the voltage of the energy storage device from becoming too high, reducing the requirements for the operating voltage of the energy storage converter and lowering production costs.

[0015] In some embodiments, the positive electrode material of the battery cell includes lithium iron phosphate, with a voltage rating of 3.1V ≤ U0 ≤ 3.3V and a capacitance of 400 ≤ Y1*Y2 ≤ 424. Thus, when the positive electrode material of the battery cell includes lithium iron phosphate, the voltage of the energy storage converter can be controlled within a reasonable range.

[0016] In some embodiments, 3.5*10 6 W≤P≤7.5*10 6 W, M = A, 1 ≤ X1 * X2 ≤ 18. The positive electrode material of the battery cell includes lithium phosphate, 3.5 * 10⁻⁶. 6 W≤P≤7.5*10 6 When W and M = A, X1*X2 can be set in the range of 1 to 18 to control the capacity of the battery cell within a reasonable range.

[0017] In some embodiments, X1 = 1.

[0018] In some embodiments, X2 = 1, 2000Ah ≤ C ≤ 11000Ah. When the positive electrode material of the battery cell includes lithium phosphate, and the number of parallel connections X1 and the number of parallel connections X2 of the battery cells in the battery compartment are both 1, setting the capacity of the battery cell in the range of 2000Ah to 11000Ah can meet both the power matching requirements and the voltage requirements of the energy storage device.

[0019] In some embodiments, 2500Ah≤C≤6000Ah.

[0020] In some embodiments, X2 = 2, 1000Ah ≤ C ≤ 5500Ah. When the positive electrode material of the battery cell includes lithium phosphate, the number of parallel connections X1 of the batteries in the battery compartment is 1, and the number of parallel connections X2 of the battery cells is 2, setting the capacity of the battery cell in the range of 1000Ah to 5500Ah can meet both the power matching requirements and the voltage requirements of the energy storage device.

[0021] In some embodiments, 2000Ah≤C≤4000Ah.

[0022] In some embodiments, 2≤X1≤6. In this way, the number of batteries connected in parallel X1 in the battery compartment is controlled within a reasonable range, which not only prevents the capacity of individual battery cells from being too large, reducing the manufacturing difficulty and cost of individual battery cells, but also prevents the number of batteries connected in parallel X1 in the battery compartment from being too large, which is conducive to improving the space utilization of the battery compartment.

[0023] In some embodiments, X1 = 4, X2 = 1, and 500Ah ≤ C ≤ 2600Ah. When the positive electrode material of the battery cell includes lithium phosphate and X1 = 4 and X2 = 1, setting the capacity of the battery cell in the range of 500Ah to 2600Ah can meet both the power matching requirements and the voltage requirements of the energy storage device.

[0024] In some embodiments, 800Ah≤C≤1500Ah.

[0025] In some embodiments, X1 = 4, X2 = 2, and 250Ah ≤ C ≤ 1300Ah. When the positive electrode material of the battery cell includes lithium phosphate and X1 = 4 and X2 = 2, setting the capacity of the battery cell in the range of 800Ah to 1500Ah can meet both the power matching requirements and the voltage requirements of the energy storage device.

[0026] In some embodiments, 350Ah≤C≤1000Ah.

[0027] In some embodiments, 500Ah≤C≤700Ah.

[0028] In some embodiments, X1 first battery packs are arranged along the length of the housing. When the positive electrode material of the battery cell includes lithium phosphate and 2≤X1≤6, arranging the X1 first battery packs connected in parallel in the battery compartment along the length of the housing can make full use of the space in the battery compartment along the length of the housing, resulting in a reasonable layout and improving the space utilization rate of the battery compartment.

[0029] In some embodiments, the battery compartment includes multiple sub-compartments arranged along the length of the housing, each sub-compartment accommodating a first battery pack. Dividing the battery compartment into multiple sub-compartments, each capable of accommodating a first battery pack, allows the first battery pack to be more regularly arranged within the battery compartment, facilitating the installation of the batteries within the first battery pack.

[0030] In some embodiments, the positive electrode material of the battery cell includes lithium transition metal oxide, with 2.8V≤U0≤4.35V and 210≤Y1*Y2≤530. Thus, when the positive electrode material of the battery cell includes lithium transition metal oxide, the voltage of the energy storage converter can be controlled within a reasonable range. This ensures that the voltage of the energy storage device is not too low, allowing it to be compatible with energy storage converters with higher operating voltages, while also preventing the voltage of the energy storage device from becoming too high, reducing the requirements for the operating voltage of the energy storage converter and lowering production costs.

[0031] In some embodiments, 3.5*10 6 W≤P≤7.5*10 6 W, M = A, 1 ≤ X1 * X2 ≤ 18. The positive electrode material of the battery cell includes lithium transition metal oxide, 3.5 * 10⁻⁶. 6 W≤P≤7.5*10 6 When W and M = A, X1*X2 can be set in the range of 1 to 18 to control the capacity of the battery cell within a reasonable range.

[0032] In some embodiments, X1 = 1.

[0033] In some embodiments, X2 = 1, 1500Ah ≤ C ≤ 13400Ah. When the positive electrode material of the battery cell includes lithium transition metal oxide, and the number of parallel connections X1 and the number of parallel connections X2 of the battery cells in the battery compartment are both 1, setting the capacity of the battery cell in the range of 1500Ah to 13400Ah can satisfy both the power matching requirements and the voltage requirements of the energy storage device.

[0034] In some embodiments, 3000Ah≤C≤7000Ah.

[0035] In some embodiments, X2 = 2, 750Ah ≤ C ≤ 6670Ah. When the positive electrode material of the battery cell includes lithium transition metal oxide, the number of parallel connections X1 of the batteries in the battery compartment is 1, and the number of parallel connections X2 of the battery cells is 2, setting the capacity of the battery cell in the range of 750Ah to 6670Ah can meet both the power matching requirements and the voltage requirements of the energy storage device.

[0036] In some embodiments, 1800Ah≤C≤4000Ah.

[0037] In some embodiments, 2≤X1≤6. In this way, the number of batteries connected in parallel X1 in the battery compartment is controlled within a reasonable range, which not only prevents the capacity of individual battery cells from being too large, reducing the manufacturing difficulty and cost of individual battery cells, but also prevents the number of batteries connected in parallel X1 in the battery compartment from being too large, which is conducive to improving the space utilization of the battery compartment.

[0038] In some embodiments, X1 = 4, X2 = 1, and 375Ah ≤ C ≤ 3300Ah. When the positive electrode material of the battery cell includes lithium transition metal oxide and X1 = 4 and X2 = 1, setting the capacity of the battery cell in the range of 375Ah to 3300Ah can satisfy both the power matching requirements and the voltage requirements of the energy storage device.

[0039] In some embodiments, 700Ah≤C≤1600Ah.

[0040] In some embodiments, X1 = 4, X2 = 2, and 200Ah ≤ C ≤ 1600Ah. When the positive electrode material of the battery cell includes lithium transition metal oxide and X1 = 4 and X2 = 2, setting the capacity of the battery cell in the range of 200Ah to 1600Ah can satisfy both the power matching requirements and the voltage requirements of the energy storage device.

[0041] In some embodiments, 340Ah≤C≤1050Ah.

[0042] In some embodiments, 490Ah≤C≤720Ah.

[0043] In some embodiments, X1 first battery packs are arranged along the length of the housing. When the positive electrode material of the battery cell includes lithium transition metal oxide and 2≤X1≤6, arranging the X1 first battery packs connected in parallel in the battery compartment along the length of the housing can make full use of the space in the battery compartment along the length of the housing, resulting in a reasonable layout and improving the space utilization rate of the battery compartment.

[0044] In some embodiments, the battery compartment includes multiple sub-compartments arranged along the length of the housing, each sub-compartment accommodating a first battery pack. Dividing the battery compartment into multiple sub-compartments, each capable of accommodating a first battery pack, allows the first battery pack to be more regularly arranged within the battery compartment, facilitating the installation of the batteries within the first battery pack.

[0045] In some embodiments, the battery cell is a sodium-ion battery cell, with 1.5V≤U0≤4V and 230≤Y1*Y2≤1000. Thus, when the battery cell is a sodium-ion battery cell, the voltage of the energy storage converter can be controlled within a reasonable range. This ensures that the voltage of the energy storage device is not too low, allowing it to be compatible with energy storage converters with higher operating voltages, while also preventing the voltage of the energy storage device from becoming too high. This reduces the requirements for the operating voltage of the energy storage converter and lowers production costs.

[0046] In some embodiments, 3.5*10 6 W≤P≤7.5*10 6 W, M = A, 1 ≤ X1 * X2 ≤ 18. The battery cell is a sodium-ion battery cell, 3.5 * 10 6 W≤P≤7.5*10 6 When W and M = A, X1*X2 can be set in the range of 1 to 18 to control the capacity of the battery cell within a reasonable range.

[0047] In some embodiments, X1 = 1.

[0048] In some embodiments, X2 = 1, 1200Ah ≤ C ≤ 18000Ah. When the battery cell is a sodium-ion battery cell, and the number of parallel connections X1 and X2 of the battery cells in the battery compartment are both 1, setting the capacity of the battery cell in the range of 1200Ah to 18000Ah can satisfy both the power matching requirements and the voltage requirements of the energy storage device.

[0049] In some embodiments, 2000Ah≤C≤10000Ah.

[0050] In some embodiments, X2 = 2, 600Ah ≤ C ≤ 9000Ah. When the battery cell is a sodium-ion battery cell, the number of parallel connections X1 in the battery compartment is 1, and the number of parallel connections X2 of the battery cells is 2, setting the capacity of the battery cell in the range of 600Ah to 9000Ah can satisfy both the power matching requirements and the voltage requirements of the energy storage device.

[0051] In some embodiments, 1600Ah≤C≤4000Ah.

[0052] In some embodiments, 2≤X1≤6. In this way, the number of batteries connected in parallel X1 in the battery compartment is controlled within a reasonable range, which not only prevents the capacity of individual battery cells from being too large, reducing the manufacturing difficulty and cost of individual battery cells, but also prevents the number of batteries connected in parallel X1 in the battery compartment from being too large, which is conducive to improving the space utilization of the battery compartment.

[0053] In some embodiments, X1 = 4, X2 = 1, and 300Ah ≤ C ≤ 4000Ah. When the battery cell is a sodium-ion battery cell and X1 = 4, X2 = 1, setting the capacity of the battery cell in the range of 300Ah to 4000Ah can satisfy both the power matching requirements and the voltage requirements of the energy storage device.

[0054] In some embodiments, 700Ah≤C≤1500Ah.

[0055] In some embodiments, X1 = 4, X2 = 2, and 150Ah ≤ C ≤ 1500Ah. When the battery cell is a sodium-ion battery cell and X1 = 4 and X2 = 2, setting the capacity of the battery cell in the range of 150Ah to 1500Ah can satisfy both the power matching requirements and the voltage requirements of the energy storage device.

[0056] In some embodiments, 350Ah≤C≤1200Ah.

[0057] In some embodiments, 400Ah≤C≤650Ah.

[0058] In some embodiments, X1 first battery packs are arranged along the length of the housing. When the individual battery cells are sodium-ion battery cells and 2≤X1≤6, arranging the X1 first battery packs connected in parallel within the battery compartment along the length of the housing can make full use of the space in the battery compartment along the length of the housing, resulting in a reasonable layout and improving the space utilization rate of the battery compartment.

[0059] In some embodiments, the battery compartment includes multiple sub-compartments arranged along the length of the housing, each sub-compartment accommodating a first battery pack. Dividing the battery compartment into multiple sub-compartments, each capable of accommodating a first battery pack, allows the first battery pack to be more regularly arranged within the battery compartment, facilitating the installation of the batteries within the first battery pack.

[0060] In some embodiments, the battery compartment accommodates only one first battery pack along the height direction of the housing. Y1 batteries in each first battery pack are arranged along the height direction of the housing, where 2 ≤ Y1 ≤ 10. Arranging all batteries in the first battery pack along the height direction of the housing facilitates series connection of all batteries in the first battery pack. Setting Y1 between 2 and 10 prevents Y1 from becoming too large. The limited number of batteries arranged along the height direction of the housing within the battery compartment improves the space utilization of the battery compartment.

[0061] In some embodiments, the battery cell includes a housing and at least one electrode assembly housed within the housing; the housing is in the shape of a right parallelepiped, with a dimension W1 in a first direction, a dimension T1 in a second direction, and a dimension K1 in a third direction. One of the three directions (first, second, and third) is parallel to the length direction of the housing, another is parallel to the width direction of the housing, and the third is parallel to the height direction of the housing; the housing includes a first wall and a second wall disposed opposite to each other along the first direction, a third wall and a fourth wall disposed opposite to each other along the second direction, and a fifth wall and a sixth wall disposed opposite to each other along the third direction. The sum of the thicknesses of the first and second walls is a, the sum of the thicknesses of the third and fourth walls is b, and the sum of the thicknesses of the fifth and sixth walls is c, satisfying: (W1-a)*(T1-b)*(K1-c) / (W1*T1*K1)≥90%. In such a battery cell, the ratio of the internal space volume of the battery cell to the total volume of the battery cell is over 90%, which results in a larger internal space ratio of the battery cell. This increases the space available in the battery cell to accommodate the electrode components, and under the same chemical system, the volumetric energy density of the battery cell can be improved.

[0062] In some embodiments, (W1-a) / W1≥97%, (T1-b) / T1≥96.5%, and (K1-c) / K1≥96.5%. This increases the dimensional proportion of the internal space of the casing in three directions, further improving the volumetric energy density of the battery cell.

[0063] In some embodiments, the housing includes a casing and an end cap, the casing having an opening and the end cap closing onto the opening; the casing includes an integrally formed first wall, a second wall, a third wall, a fourth wall, and a fifth wall, and the end cap is a sixth wall. When assembling the battery, the electrode terminals can be installed onto the end cap first, then the electrode assembly can be housed within the casing, and finally the end cap can be closed onto the opening of the casing, which reduces the difficulty of installing the electrode assembly into the casing and the difficulty of installing the electrode terminals into the casing.

[0064] In some embodiments, the battery cell further includes a first insulating member and a second insulating member. The first insulating member is disposed between the fifth wall and the electrode assembly and abuts against the fifth wall; the second insulating member is disposed between the sixth wall and the electrode assembly and abuts against the sixth wall. The maximum dimension of the first insulating member in the third direction is e1, and the maximum dimension of the second insulating member in the third direction is e2, satisfying: (W1-a-1.6mm)*(T1-b-1.6mm)*(K1-c-e1-e2) / (W1*T1*K1)≥88%, 0.3mm≤e1≤1.2mm, and 2mm≤e2≤10mm. This increases the internal space of the casing for the electrode assembly, allowing for a larger electrode assembly to be accommodated, thereby further improving the volumetric energy density of the battery cell.

[0065] In some embodiments, the battery cell further includes a first insulating member and a second insulating member. The first insulating member is disposed between the fifth wall and the electrode assembly and abuts against the fifth wall; the second insulating member is disposed between the sixth wall and the electrode assembly and abuts against the sixth wall. The maximum dimension of the first insulating member in the third direction is e1, and the maximum dimension of the second insulating member in the third direction is e2, satisfying: (W1-a-4mm)*(T1-b-4mm)*(K1-c-e1-e2) / (W1*T1*K1)≥85%, 0.3mm≤e1≤1.2mm, and 2mm≤e2≤10mm. This increases the internal space of the casing for the electrode assembly, allowing for a larger electrode assembly to be accommodated, thereby further improving the volumetric energy density of the battery cell.

[0066] In some embodiments, W1≥T1, the first direction is parallel to the length direction of the housing, the second direction is parallel to the width direction of the housing, and the third direction is parallel to the height direction of the housing. When the housing has an end cap at only one end and W1≥T1, setting the end cap and the fifth wall of the housing opposite each other along the height direction of the housing, setting the first and second walls of the housing opposite each other along the length direction of the housing, and setting the third and fourth walls of the housing opposite each other along the width direction of the housing helps to increase the volume ratio of all battery cells in the battery compartment.

[0067] In some embodiments, the housing includes a housing and two end caps, the housing having two openings disposed opposite each other in a third direction, the two end caps respectively covering the two openings; the housing includes an integrally formed first wall, a second wall, a third wall and a fourth wall, and the two end caps are a fifth wall and a sixth wall respectively.

[0068] In some embodiments, the battery cell further includes a third insulating member and a fourth insulating member. The third insulating member is disposed between the fifth wall and the electrode assembly and abuts against the fifth wall; the fourth insulating member is disposed between the sixth wall and the electrode assembly and abuts against the sixth wall. The maximum dimension of the third insulating member in the third direction is e3, and the maximum dimension of the fourth insulating member in the third direction is e4, satisfying: (W1-a-1.6mm)*(T1-b-1.6mm)*(K1-c-e3-e4) / (W1*T1*K1)≥88%, 2mm≤e3≤10mm, and 2mm≤e4≤10mm. This increases the space left inside the casing for the electrode assembly, allowing for the accommodation of a larger electrode assembly, thereby further improving the volumetric energy density of the battery cell.

[0069] In some embodiments, the battery cell further includes a third insulating member and a fourth insulating member. The third insulating member is disposed between the fifth wall and the electrode assembly and abuts against the fifth wall; the fourth insulating member is disposed between the sixth wall and the electrode assembly and abuts against the sixth wall. The maximum dimension of the third insulating member in the third direction is e3, and the maximum dimension of the fourth insulating member in the third direction is e4, satisfying: (W1-a-4mm)*(T1-b-4mm)*(K1-c-e3-e4) / (W1*T1*K1)≥85%, 2mm≤e3≤10mm, and 2mm≤e4≤10mm. This increases the space left inside the casing for the electrode assembly, allowing for a larger electrode assembly to be accommodated, thereby further improving the volumetric energy density of the battery cell.

[0070] In some embodiments, W1≥T1, the first direction is parallel to the height direction of the housing, the second direction is parallel to the width direction of the housing, and the third direction is parallel to the length direction of the housing. When end caps are provided at both ends of the housing and W1≥T1, arranging the two end caps along the length direction of the housing, arranging the first and second walls along the height direction of the housing, and arranging the third and fourth walls opposite each other along the width direction of the housing helps to increase the volume ratio of all battery cells within the battery compartment.

[0071] In some embodiments, 3000cm 3 ≤W1*T1*K1≤40000cm 3 W1*T1*K1≥3000cm 3 This ensures that, while maintaining a ratio of internal space volume to outer shell volume of over 90%, the outer shell wall thickness is not too small, thus meeting the structural strength requirements for the outer shell; W1*T1*K1≤40000cm 3 This allows the capacity and current of individual battery cells to be controlled within a suitable range, reducing the risk of damage to overcurrent components in the circuit.

[0072] In some embodiments, 3200cm 3 ≤W1*T1*K1≤32000cm 3 It balances the structural strength of the casing with the heat dissipation requirements of individual battery cells, further improving the structural strength of the casing and reducing the risk of damage to overcurrent components in the circuit.

[0073] In some embodiments, 3720cm 3 ≤W1*T1*K1≤12500cm 3 .

[0074] In some embodiments, 4000cm 3 ≤W1*T1*K1≤6000cm 3 .

[0075] In some embodiments, the positive electrode material of the battery cell includes lithium phosphate, satisfying: C ≥ 350 Ah, C / ((W1-a)*(T1-b)*(K1-c)) ≥ 118 Ah / L. When the positive electrode material of the battery cell includes lithium phosphate and C ≥ 350 Ah, setting C / ((W1-a)*(T1-b)*(K1-c)) above 118 Ah / L can increase the volume ratio of the internal space of the battery cell casing, which is beneficial to achieving a ratio of internal space volume to casing volume of the battery cell casing of more than 90%.

[0076] In some embodiments, the positive electrode material of the battery cell includes lithium transition metal oxide, satisfying: C ≥ 650 Ah, C / ((W1-a)*(T1-b)*(K1-c)) ≥ 190 Ah / L. When the positive electrode material of the battery cell includes lithium transition metal oxide and C ≥ 650 Ah, setting C / ((W1-a)*(T1-b)*(K1-c)) above 190 Ah / L can increase the volume ratio of the internal space of the battery cell's casing, which is beneficial for achieving a ratio of internal space volume to casing volume of the battery cell of over 90%.

[0077] In some embodiments, the battery cell is a sodium-ion battery cell, satisfying: C≥260Ah, C / ((W1-a)*(T1-b)*(K1-c))≥87Ah / L. When the battery cell is a sodium-ion battery cell and C≥260Ah, setting C / ((W1-a)*(T1-b)*(K1-c)) above 87Ah / L can increase the volume ratio of the internal space of the battery cell's casing, which is beneficial for achieving a ratio of internal space volume to casing volume of over 90%.

[0078] Secondly, embodiments of this application provide an energy storage system, including an energy storage converter and M energy storage devices provided in any one of the embodiments of the first aspect, wherein the energy storage devices are electrically connected to the energy storage converter.

[0079] In some embodiments, M = 2, A = 2; or, M = 4, A = 4; or, M = 8, A = 8. Attached Figure Description

[0080] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0081] Figure 1 Schematic block diagram of an energy storage system provided for some embodiments of this application;

[0082] Figure 2 Axonometric views of energy storage devices provided in some embodiments of this application;

[0083] Figure 3 This is a schematic diagram of the structure of an energy storage device provided in some embodiments of this application;

[0084] Figure 4 for Figure 3 The diagram shows the structure of the box.

[0085] Figure 5 for Figure 4 The box shown is a cross-sectional view (AA section).

[0086] Figure 6 for Figure 3 The exploded view of the battery shown;

[0087] Figure 7 for Figure 6 The exploded view of the battery cell shown;

[0088] Figure 8 for Figure 3 The diagram shows the battery layout inside the battery compartment.

[0089] Figure 9 A diagram showing the arrangement of batteries within a battery compartment as provided in other embodiments of this application;

[0090] Figure 10 This application provides schematic diagrams of the battery structure for some embodiments.

[0091] Figure 11 This is a schematic diagram of the battery structure provided in some other embodiments of this application;

[0092] Figure 12 Schematic diagrams of the energy storage device provided in other embodiments of this application;

[0093] Figure 13 for Figure 12 The diagram shows the structure of the box.

[0094] Figure 14 for Figure 12 The diagram shows a BB cross-sectional view of the energy storage device.

[0095] Figure 15 Axonometric views of a single battery cell provided in some embodiments of this application;

[0096] Figure 16 for Figure 15The exploded view of the battery cell shown;

[0097] Figure 17 for Figure 15 The exploded cross-sectional view of the battery cell shown is taken along the UW plane.

[0098] Figure 18 for Figure 15 The exploded cross-sectional view of the battery cell shown is taken along the VW plane.

[0099] Figure 19 Axonometric views of a battery cell provided for other embodiments of this application;

[0100] Figure 20 for Figure 19 The exploded view of the battery cell shown;

[0101] Figure 21 for Figure 19 The exploded cross-sectional view of the battery cell shown is taken along the UW plane.

[0102] Figure 22 for Figure 19 The exploded cross-sectional view of the battery cell shown is taken along the VW plane.

[0103] Icons: 1-Box body; 11-Battery compartment; 111-Sub-compartment; 112-Separator; 113-Supporting component; 12-Thermal management compartment; 13-Main control compartment; 14-Electrical compartment; 2-Battery; 2a-First battery pack; 2b-Second battery pack; 21-Battery cell; 21a-First battery cell group; 21b-Second battery cell group; 211-Outer casing; 2111-Shell; 2112-End cap; 2113-First wall; 2114-Second wall; 2115-Third wall; 2116-Fourth wall; 2117-... Fifth wall; 2118-Sixth wall; 212-Electrode terminal; 213-Electrode assembly; 2131-Taper; 214-First insulating component; 215-Second insulating component; 216-Third insulating component; 217-Fourth insulating component; 22-Battery box; 221-First part; 222-Second part; 10-Energy storage device; 20-Energy storage converter; 100-Energy storage system; U-First direction; V-Second direction; W-Third direction; X-Length direction of the box; Y-Width direction of the box; Z-Height direction of the box. Detailed Implementation

[0104] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0105] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0106] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0107] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0108] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0109] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0110] In this application, "multiple" means two or more (including two).

[0111] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0112] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0113] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, reduces the risk of short circuits while allowing active ions to pass through.

[0114] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0115] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0116] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0117] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.

[0118] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0119] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0120] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0121] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0122] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0123] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0124] In some implementations, the electrode assembly is a wound structure.

[0125] In some implementations, the electrode assembly is a stacked structure.

[0126] The energy storage device 10 is a device that integrates multiple battery cells 21 within a housing 1. The multiple battery cells 21 are connected in series, parallel, or mixed to store electrical energy. The energy storage device 10 can be used in power systems to store surplus electrical energy during off-peak periods to supplement electricity consumption during peak periods.

[0127] Energy storage device 10 typically needs to be connected to energy storage converter 20. External devices (such as the power grid) can convert AC power to DC power through energy storage converter 20 and store it in energy storage device 10 to charge it. Conversely, energy storage device 10 can also convert DC power to AC power through energy storage converter 20 to supply power to external devices, thus discharging it. However, for typical energy storage devices 10, the matching between the energy storage device 10 and energy storage converter 20 is not considered, and insufficient power margin is not provided. This necessitates capacity expansion of the energy storage device 10 within a short period of use, for example, by adding additional battery cells 21 to the original energy storage device 10. This results in poor power matching between the energy storage device 10 and energy storage converter 20.

[0128] In view of this, this application provides an energy storage device 10 for electrically connecting to an energy storage converter 20. The energy storage converter 20 can be used to cooperate with M energy storage devices 10, where M is a positive integer. The rated output power of the energy storage converter 20 is P (in W), the energy of the energy storage device 10 is Q (in Wh), and the time for the energy storage device 10 to discharge from a fully charged state to a fully discharged state is A (in hours). P / (M*Q / A) is set in the range of 0.7 to 0.99. In this way, the long-term reliability and economy of the energy storage device 10 are taken into account, and the power matching between the energy storage device 10 and the energy storage converter 20 is improved.

[0129] The energy storage device 10 described in the embodiments of this application is applicable to the energy storage system 100.

[0130] Please refer to Figure 1 , Figure 1 This is a schematic block diagram of an energy storage system 100 provided for some embodiments of this application. The energy storage system 100 may include an energy storage device 10 and an energy storage converter 20 (PCS, Power Conversion System), with the energy storage device 10 and the energy storage converter 20 electrically connected.

[0131] The energy storage converter 20 is a device that connects external equipment and the energy storage device 10. The external equipment can be the power grid, electrical equipment, etc. The energy storage converter 20 has a DC side and an AC side. The DC side is used for electrical connection with the energy storage device 10, and the AC side is used for connection with the external equipment.

[0132] When the energy storage device 10 is in the charging state, the energy storage converter 20 acts as a rectifier to convert the electrical energy from the AC power on the AC side into DC power and store it in the energy storage device 10. When the energy storage device 10 is in the discharging state, the energy storage converter 20 acts as an inverter to convert the electrical energy stored in the energy storage device 10 from the DC power on the DC side into AC power and deliver it to external equipment.

[0133] In the energy storage system 100, one energy storage converter 20 can correspond to one energy storage device 10, or multiple energy storage devices 10 can be configured. In an embodiment where one energy storage converter 20 corresponds to multiple energy storage devices 10, the energy storage devices 10 can be two, three, four, five, six, seven, eight, or more. As an example, in... Figure 1 In this configuration, one energy storage converter 20 is electrically connected to four energy storage devices 10.

[0134] The specific structure of the energy storage device 10 provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0135] Please refer to Figure 2 , Figure 2 This is an isometric view of an energy storage device 10 provided in some embodiments of this application. Embodiments of this application provide an energy storage device 10 for electrical connection to an energy storage converter 20. The energy storage converter 20 can be used to cooperate with M energy storage devices 10, where M is a positive integer. The rated output power of the energy storage converter 20 is P (in W), the energy of the energy storage device 10 is Q (in Wh), and the time it takes for the energy storage device 10 to discharge from a fully charged state to a fully discharged state is A (in hours), satisfying: 0.7 ≤ P / (M*Q / A) ≤ 0.99.

[0136] The rated output power of the energy storage converter 20 is the rated output power of the AC side of the energy storage converter 20. The rated output power of the energy storage converter 20 is represented by P, and the unit is "watt", abbreviated as "W". The energy of the energy storage device 10 is represented by Q, and the unit is "watt-hour", abbreviated as "Wh". The time it takes for the energy storage device 10 to discharge from a fully charged state to a fully discharged state is represented by A, and the unit is "hour", abbreviated as "h".

[0137] It is understandable that when the energy storage device 10 is fully charged, it is in a fully charged state; when the energy storage device 10 is depleted, it is in a fully discharged state. The time it takes for the energy storage device 10 to discharge from the fully charged state to the fully discharged state through the energy storage converter 20 is represented by A, and the unit is "hours", with the symbol "h".

[0138] M can be 1, 2, 3, 4, 5, 6, 7, 8, etc. M can be equal to A, greater than A, or less than A.

[0139] M*Q represents the total energy of the M energy storage devices 10 that cooperate with the energy storage converter 20, and M*Q / A represents the power of the M energy storage devices 10 that cooperate with the energy storage converter 20.

[0140] P / (M*Q / A) can be any point value of 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 0.99, or any range between two values.

[0141] In this embodiment, P / (M*Q / A)≤0.99 ensures that the power of all energy storage devices 10 cooperating with the energy storage converter 20 has sufficient margin compared to the power of the energy storage converter 20, eliminating the need for capacity expansion of the energy storage devices 10 over a longer period, thus achieving long-term reliability of the energy storage devices 10. P / (M*Q / A)≥0.7 ensures that the margin between the power of the energy storage devices 10 and the power of the energy storage converter 20 is not excessive, reducing power waste and improving the economic efficiency of the energy storage devices 10. Thus, from the perspective of long-term reliability and economic efficiency of the energy storage devices 10, the power matching between the energy storage devices 10 and the energy storage converter 20 is improved.

[0142] The following is a detailed explanation using experimental data:

[0143] Table 1

[0144]

[0145] According to Table 1 above, comparing Examples 1-9 and Comparative Example 1, it can be seen that when P / (M*Q / A)≤0.99, the capacity replenishment cycle of the energy storage device 10 is relatively long, and there is no need to replenish the capacity of the energy storage device 10 in a short period of time, thus achieving long-term reliability of the energy storage device 10.

[0146] In some embodiments, 0.75 ≤ P / (M*Q / A) ≤ 0.95.

[0147] In this embodiment, P / (M*Q / A) can be any point value or a range value between any two of the following: 0.75, 0.78, 0.8, 0.83, 0.85, 0.88, 0.9, 0.93, 0.95.

[0148] In this embodiment, 0.75≤P / (M*Q / A)≤0.95, which takes into account both the long-term reliability and economy of the energy storage device 10. It can keep the cost of the energy storage device 10 at a low level and extend the capacity replenishment cycle of the energy storage device 10.

[0149] In some embodiments, 0.85 ≤ P / (M*Q / A) ≤ 0.93.

[0150] In this embodiment, P / (M*Q / A) can be any point value of 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, or a range value between any two.

[0151] In this embodiment, 0.85≤P / (M*Q / A)≤0.93 further balances the long-term reliability and economy of the energy storage device 10, which can not only further control the cost of the energy storage device 10 at a low level, but also further extend the capacity replenishment cycle of the energy storage device 10.

[0152] In some embodiments, please refer to Figures 3-6 , Figure 3 This is a schematic diagram of the structure of the energy storage device 10 provided in some embodiments of this application; Figure 4 for Figure 3 The diagram shows the structure of box 1. Figure 5 for Figure 4 The AA section view of box 1 shown; Figure 6 for Figure 3 The exploded view of battery 2 is shown. The energy storage device 10 includes a housing 1 and at least one battery 2. The housing 1 includes a battery compartment 11, in which at least one battery 2 is housed. Each battery 2 includes at least one individual battery cell 21. The capacity of each individual battery cell 21 is C (Ah), the plateau voltage of each individual battery cell 21 is U0 (V), and the total number of individual battery cells 21 in the battery compartment 11 is N, where Q = N * C * U0.

[0153] The capacity of battery cell 21 is represented by C, and the unit is "ampere-hour" (Ah). The plateau voltage of battery cell 21 is represented by U0, and the unit is "volt" (V). Plateau voltage refers to the voltage value corresponding to the smallest voltage change and the largest capacity change of battery cell 21.

[0154] The container 1 can be a standard component conforming to international standards set by the International Organization for Standardization (ISO), or it can be a non-standard component. The container 1 can also be called a shipping container, and the energy storage device 10 can also be called an energy storage container. The container 1 can have various shapes, such as cylindrical or prismatic. As an example, Figure 3 In the middle, box 1 is a quadrangular prism, specifically, box 1 is a cuboid.

[0155] Battery compartment 11 is the space inside housing 1 used to house battery 2. Battery compartment 11 can hold only battery 2, or it can hold other components besides battery 2, such as fire-fighting components, which may include pipes, detectors, etc. Battery compartment 11 can have various shapes, such as cylindrical, prismatic, etc. Prismatic shapes can be triangular, square, pentagonal, hexagonal, etc. As an example, in... Figures 3-5In this design, the battery compartment 11 is a quadrangular prism, specifically, the battery 2 is a cuboid. Taking the cuboid shape of the battery compartment 11 as an example, at least one side of the battery compartment 11 has an opening along the width direction Y of the housing, through which the battery 2 can enter the battery compartment 11. A door can be correspondingly provided on the opening side of the battery compartment 11. The door can be slidably connected to the housing 1, hinged, etc., so that the opening can be opened or closed by sliding or rotating.

[0156] The enclosure 1 may contain only a battery compartment 11, or it may contain additional spaces for accommodating other components. For example, the enclosure 1 may also include a thermal management compartment 12 and a main control compartment 13. The thermal management compartment 12 may house a water-cooled unit, which provides a fluid medium for the thermal management components, which may be water-cooled plates located within the battery compartment 11 to manage the temperature of the individual battery cells 21. The main control compartment 13 may house a main control unit, which is used for high-voltage control and communication of the multiple battery cells 21 within the battery compartment 11. The enclosure 1 is rectangular, with the battery compartment 11 and main control compartment 13 arranged along the height direction Z of the enclosure. The thermal management compartment 12 may be located on one side of the battery compartment 11 along the length direction X of the enclosure, and the main control compartment 13 may be located at the bottom of the battery compartment 11 along the height direction Z. In other embodiments, the enclosure 1 may also include an electrical compartment 14, which may house a combiner unit, a power distribution unit, and a control unit. The current combining unit is used to combine multiple batteries 2, enabling a safe connection between the multiple batteries 2 and the DC side of the energy storage converter 20. The power distribution unit can draw power from the grid to supply power to the internal control system and auxiliary systems; the control unit may include a battery cell 21 management unit, a fire control unit, etc., for monitoring and managing the internal components of the energy storage device 10. The electrical compartment 14 and the thermal management compartment 12 can be located on one side of the battery compartment 11 along the length direction X of the enclosure, and the electrical compartment 14 and the thermal management compartment 12 are arranged along the width direction Y of the enclosure.

[0157] The battery compartment 11 can contain one or more batteries 2, and the battery cells 21 within the battery 2 can also contain one or more individual cells. The batteries 2 within the battery compartment 11 can be connected in series, parallel, or a combination of both. The battery cells 21 within the battery 2 can also be connected in series, parallel, or a combination of both. A combination of both means that they are connected in both series and parallel configurations.

[0158] It is understandable that if the number of battery cells 21 in each battery 2 is equal, the number N of battery cells 21 in the battery compartment 11 is equal to the number of batteries 2 in the battery compartment 11 multiplied by the number of battery cells 21 in the battery 2. If there is only one battery 2 in the battery compartment 11, and there is only one battery cell 21 in the battery 2, then the battery compartment 11 can only hold one battery cell 21, and N = 1.

[0159] Along the length direction X of the housing, the battery compartment 11 can accommodate one battery 2 or multiple batteries 2; along the width direction Y of the housing, the battery compartment 11 can accommodate one battery 2 or multiple batteries 2; along the height direction Z of the housing, the battery compartment 11 can accommodate one battery 2 or multiple batteries 2. The battery 2 can be cuboid in shape. After being placed in the battery compartment 11, the battery 2 can be positioned such that one of its length, width, or height directions is parallel to the length direction X of the housing, another is parallel to the width direction Y of the housing, and yet another is parallel to the height direction Z of the housing. As an example, in... Figure 3 In the illustrated embodiment, along the length direction X of the housing, the battery compartment 11 contains a plurality of batteries 2; along the height direction Z of the housing, the battery compartment 11 contains a plurality of batteries 2; along the width direction Y of the housing, the battery compartment 11 contains only one battery 2, the length direction of the battery 2 is parallel to the width direction Y of the housing, the width direction of the battery 2 is parallel to the length direction X of the housing, and the height direction of the battery 2 is parallel to the height direction Z of the housing.

[0160] In this embodiment, Q = N*C*U0, ensuring that all battery cells 21 in the battery compartment 11 have the same capacity, allowing the selection of battery cells 21 of the same specification. On one hand, this improves the assembly efficiency of the energy storage device 10; on the other hand, it reduces the probability of wasted space due to different specifications of the battery cells 21 within the battery compartment 11.

[0161] In some embodiments, the battery 2 can be a battery module. For example, the battery 2 may contain multiple battery cells 21, which are arranged and fixed to form a battery module. In the battery module, a frame can be formed by two side plates and two end plates, and the battery cells 21 are fixed in the frame to form the battery module.

[0162] In other embodiments, such as Figure 6As shown, battery 2 can also be a battery pack, and battery 2 can also include a battery box 22, in which individual battery cells 21 are housed. If there are multiple individual battery cells 21 in battery 2, the multiple individual battery cells 21 can be arranged in an array within battery box 22. Battery box 22 can include a first part 221 and a second part 222, which overlap each other to define a space for accommodating individual battery cells 21. The first part 221 and the second part 222 can be of various shapes, such as cuboid or cylindrical. The first part 221 can be a hollow structure open on one side, and the second part 222 can also be a hollow structure open on one side. The open side of the second part 222 overlaps the open side of the first part 221, thus forming a battery box 22 with a accommodating space. Alternatively, the first part 221 can be a hollow structure open on one side, and the second part 222 can be a plate-like structure. The second part 222 overlaps the open side of the first part 221, thus forming a battery box 22 with a accommodating space. The first part 221 and the second part 222 can be sealed by a sealing element, such as a sealing ring or sealant.

[0163] In some embodiments, please refer to Figure 7 , Figure 7 for Figure 6 The diagram shows an exploded view of a battery cell 21. The battery cell 21 may include a housing 211, an electrode assembly 213, and electrode terminals 212. The electrode terminals 212 are disposed on the housing 211 and are electrically connected to the electrode assembly 213.

[0164] The outer casing 211 is a component used to house the electrode assembly 213 and electrolyte, etc. The outer casing 211 can be cylindrical or prismatic. Prisms include triangular prisms, square prisms, pentagonal prisms, or hexagonal prisms, etc. Square prisms include oblique square prisms, right parallelepipeds, etc. Right parallelepipeds include cuboids, cubes, etc. As an example, the outer casing 211 may include a housing 2111 and an end cap 2112.

[0165] The shell 2111 can be a hollow structure with an opening at one end, or it can be a hollow structure with openings at both opposite ends. The shell 2111 can have various shapes, such as cylindrical or prismatic. The shell 2111 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, or plastic.

[0166] End cap 2112 is a component that closes the opening of housing 2111 to isolate the internal environment of battery cell 21 from the external environment. End cap 2112 and housing 2111 together define a receiving space for accommodating electrode assembly 213, electrolyte, and other components. The shape of end cap 2112 can be adapted to the shape of housing 211. For example, if housing 2111 is a cuboid structure, end cap 2112 can be a rectangular plate structure adapted to housing 2111; or if housing 2111 is a cylindrical structure, end cap 2112 can be a circular plate structure adapted to housing 2111. End cap 2112 can also be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, or plastic. The materials of end cap 2112 and housing 2111 can be the same or different.

[0167] In an embodiment where the housing 2111 has an opening at one end, one end cap 2112 may be provided. In an embodiment where the housing 2111 has openings at opposite ends, two end caps 2112 may be provided, with the two end caps 2112 respectively closing the two openings of the housing 2111, and the two end caps 2112 and the housing 2111 together defining the receiving space.

[0168] Electrode terminal 212 is a component in battery cell 21 used for inputting or outputting electrical energy. Electrode terminal 212 is disposed on housing 211 and is used for electrical connection with tab 2131 of electrode assembly 213. Electrode terminal 212 can be disposed on housing 2111 or end cap 2112 of housing 211. Electrode terminal 212 and tab 2131 can be directly connected, for example, by direct welding; or they can be indirectly connected through current collector, which can be a metallic conductor, such as copper, iron, aluminum, steel, or aluminum alloy.

[0169] As an example, such as Figure 7 As shown, the housing 2111 is a hollow structure with an opening at one end. There is only one end cap 2112 in the housing 211. The end cap 2112 closes the opening of the housing 2111. The end cap 2112 is provided with two electrode terminals 212. The electrode terminals 212 protrude from the outer surface of the end cap 2112. The end of the electrode assembly 213 facing the end cap 2112 has a positive electrode tab 2131 and a negative electrode tab 2131. The positive electrode tab 2131 and the negative electrode tab 2131 are electrically connected to the two electrode terminals 212 respectively.

[0170] Taking the rectangular parallelepiped shape of the outer casing 211 of the battery cell 21 as an example, the outer casing 211 has a length direction, a width direction, and a height direction. The length of the outer casing 211 is greater than or equal to the width of the outer casing 211, and the electrode terminal 212 is located at one end of the outer casing 211 in the height direction. After the battery 2 is housed in the battery compartment 11, one of the three directions of the outer casing 211—length direction, width direction, and height direction—can be parallel to the length direction X of the casing, another parallel to the width direction Y of the casing, and the third parallel to the height direction Z of the casing.

[0171] In some embodiments, please refer to Figures 8-10 , Figure 8 for Figure 3 The diagram shows the arrangement of batteries 2 inside battery compartment 11; Figure 9 A diagram showing the arrangement of batteries 2 within the battery compartment 11 as provided in other embodiments of this application; Figure 10 This is a schematic diagram of the structure of battery 2 provided in some embodiments of this application; Figure 11 This is a schematic diagram of the structure of the battery 2 provided in some other embodiments of this application. The battery compartment 11 contains N1 batteries 2, which are formed by X1 first battery packs 2a connected in parallel, and each first battery pack 2a is formed by Y1 batteries 2 connected in series; or, N1 batteries 2 are formed by Y1 second battery packs 2b connected in series, and each second battery pack 2b is formed by X1 batteries 2 connected in parallel, satisfying: N1≥1, X1≥1, Y1≥1, N1=X1*Y1. Battery 2 comprises N2 battery cells 21, which are formed by X2 first battery cell groups 21a connected in parallel, and each first battery cell group 21a is formed by Y2 battery cells 21 connected in series; or, N2 battery cells 21 are formed by Y2 second battery cell groups 21b connected in series, and each second battery cell group 21b is formed by X2 battery cells 21 connected in parallel, satisfying: N2≥1, X2≥1, Y2≥1, N2=X2*Y2, N=N1*N2.

[0172] X1 represents the number of batteries 2 connected in parallel within battery compartment 11, and Y1 represents the number of batteries 2 connected in series within battery compartment 11. X2 represents the number of individual battery cells 21 connected in parallel within battery 2, and Y2 represents the number of individual battery cells 21 connected in series within battery 2. N1, N2, X2, and Y2 are integers greater than or equal to 1.

[0173] If X1 = 1, N1 batteries 2 formed by X1 parallel-connected first battery packs 2a are equivalent to N1 batteries 2 formed by 1 first battery pack 2a; each second battery pack 2b formed by X1 parallel-connected batteries 2 is equivalent to each second battery pack 2b formed by 1 battery 2. If Y1 = 1, each first battery pack 2a formed by Y1 series-connected batteries 2 is equivalent to each first battery pack 2a formed by 1 battery 2; N1 batteries 2 formed by Y1 series-connected second battery packs 2b are equivalent to N1 batteries 2 formed by 1 second battery pack 2b.

[0174] If X2 = 1, N2 battery cells 21 formed by X2 parallel-connected first battery cell groups 21a are equivalent to N2 battery cells 21 formed by 1 first battery cell group 21a; each second battery cell group 21b formed by X2 parallel-connected battery cells 21 is equivalent to each second battery cell group 21b formed by 1 battery cell 21. If Y2 = 1, each first battery cell group 21a formed by Y2 series-connected battery cells 21 is equivalent to each first battery cell group 21a formed by 1 battery cell 21; N2 battery cells 21 formed by Y2 series-connected second battery cell groups 21b are equivalent to N2 battery cells 21 formed by 1 second battery cell group 21b.

[0175] exist Figure 8 In the illustrated embodiment, N1 batteries 2 are formed by X1 first battery packs 2a connected in parallel, and each first battery pack 2a is formed by Y1 batteries 2 connected in series. As an example, X1 = 4, Y1 = 8.

[0176] exist Figure 9 In the illustrated embodiment, N1 batteries 2 are formed by Y1 second battery packs 2b connected in series, and each second battery pack 2b is formed by X1 batteries 2 connected in parallel. As an example, X1 = 4, Y1 = 8.

[0177] exist Figure 10 In the illustrated embodiment, N2 battery cells 21 are formed by X2 parallel-connected first battery cell groups 21a, and each first battery cell group 21a is formed by Y2 battery cells 21 connected in series. There are multiple battery cells 21 within the battery box 22, arranged in an array. Each row of battery cells 21 is arranged along the length X of the box, and each column of battery cells 21 is arranged along the width Y of the box. As an example, all battery cells 21 in every two columns are connected in series to form one first battery cell group 21a. Specifically, the battery cells 21 within the battery box 22 are arranged in 26 rows and 4 columns, where X2 = 2 and Y2 = 52.

[0178] exist Figure 11In the illustrated embodiment, N2 battery cells 21 are formed by Y2 second battery cell groups 21b connected in series, and each second battery cell group 21b is formed by X2 battery cells 21 connected in parallel. There are multiple battery cells 21 within the battery box 22, arranged in an array. Each row of battery cells 21 is arranged along the length X of the box, and each column of battery cells 21 is arranged along the width Y of the box. As an example, in each column of battery cells 21, every two battery cells 21 are connected in parallel to form a second battery cell group 21b. Specifically, the battery cells 21 within the battery box 22 are arranged in 26 rows and 4 columns, X2 = 2, Y2 = 52.

[0179] In this embodiment, for the N1 batteries 2 in the battery compartment 11, Y1 batteries 2 can be connected in series to form a first battery pack 2a, and then X1 first battery packs 2a can be connected in parallel; alternatively, X1 batteries 2 can be connected in parallel to form a second battery pack 2b, and then Y1 second battery packs 2b can be connected in series. For the N2 battery cells 21 in the battery 2, Y2 battery cells 21 can be connected in series to form a first battery cell group 21a, and then X2 first battery cell groups 21a can be connected in parallel; alternatively, X2 battery cells 21 can be connected in parallel to form a second battery cell group 21b, and then Y2 second battery cell groups 21b can be connected in series. The number of batteries 2 connected in series Y1 and the number of battery cells 21 connected in series Y2 in the battery compartment 11 can be set according to requirements to adjust the voltage of the energy storage device 10 to a reasonable range.

[0180] In some embodiments, when the energy storage device 10 is charging, the maximum operating voltage on the DC side of the energy storage converter 20 is U1, and the minimum operating voltage on the DC side of the energy storage converter 20 is U2, satisfying: U2 < U0 * Y1 * Y2 < U1.

[0181] When an external device charges the energy storage device 10 through the energy storage converter 20, the operating voltage on the DC side of the energy storage converter 20 gradually changes with the charging status of the energy storage device 10. For example, the operating voltage on the DC side of the energy storage converter 20 gradually increases. U1 is the maximum operating voltage of the energy storage converter 20 when charging, and U2 is the minimum operating voltage of the energy storage converter 20 when charging.

[0182] Wherein, U0*Y1*Y2 is the voltage of the energy storage device 10.

[0183] In this embodiment, U0*Y1*Y2 < U1, which allows external devices to charge the energy storage device 10 normally through the energy storage converter 20; U0*Y1*Y2 > U2, which allows the energy storage device 10 to supply power to external devices through the energy storage converter 20. Therefore, by controlling U0*Y1*Y2 within the range of U2 to U1, the voltage of the energy storage converter 20 is matched with the voltage of the energy storage converter 20, which allows both external devices to charge the energy storage device 10 through the energy storage converter 20 and the energy storage device 10 to supply power to external devices through the energy storage converter 20.

[0184] In some embodiments, the positive electrode material of the battery cell 21 includes lithium phosphate, 2.8V≤U0≤3.6V, and 250≤Y1*Y2≤468.

[0185] Lithium-containing phosphates include, but are not limited to, at least one of the following: lithium iron phosphate (such as LiFePO4 (also known as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0186] In this embodiment, U0 can be any one of the following values: 2.8V, 2.9V, 3V, 3.1V, 3.2V, 3.3V, 3.4V, 3.5V, 3.6V, or a range between any two. Y1*Y2 can be any one of the following values: 250, 256, 280, 288, 300, 304, 320, 336, 360, 384, 400, 416, 440, 468, or a range between any two.

[0187] In this embodiment, when the positive electrode material of the battery cell 21 includes lithium phosphate, 2.8V≤U0≤3.6V and 250≤Y1*Y2≤468 can control the voltage of the energy storage converter 20 within a reasonable range. This ensures that the voltage of the energy storage device 10 is not too low, allowing the energy storage device 10 to be compatible with the energy storage converter 20, which has a higher operating voltage, while also preventing the voltage of the energy storage device 10 from being too high. This reduces the requirements for the operating voltage of the energy storage converter 20 and lowers production costs.

[0188] In some embodiments, the positive electrode material of the battery cell 21 includes lithium iron phosphate, with 3.1V≤U0≤3.3V and 400≤Y1*Y2≤424.

[0189] In this embodiment, U0 can be any one of the following values: 3.1V, 3.13V, 3.15V, 3.18V, 3.2V, 3.23V, 3.25V, 3.28V, 3.3V, etc., or a range between any two. Y1*Y2 can be any one of the following values: 400, 404, 408, 412, 416, 420, 424, etc., or a range between any two.

[0190] In this embodiment, when the positive electrode material of the battery cell 21 includes lithium iron phosphate, 3.1V≤U0≤3.3V and 400≤Y1*Y2≤424, the voltage of the energy storage converter 20 can be controlled within a reasonable range.

[0191] In some embodiments, 3.5*10 6 W≤P≤7.5*10 6 W, M = A, 1 ≤ X1 * X2 ≤ 18.

[0192] P can be 3.5 * 10 6 W, 3.75*10 6 W, 4*10 6 W, 4.2*10 6 W, 4.5*10 6 W, 4.9*10 6 W, 5*10 6 W, 5.2*10 6 W, 5.5*10 6 W, 5.8*10 6 W, 6*10 6 W, 6.2*10 6 W, 6.8*10 6 W, 7*10 6 W, 7.2*10 6 W, 7.5*10 6 The value of any one of W or any range between two of them. X1*X2 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18.

[0193] In this embodiment, the positive electrode material of the battery cell 21 includes lithium phosphate, 3.5*10 6 W≤P≤7.5*10 6 When W and M = A, X1*X2 can be set in the range of 1 to 18 to control the capacity of the battery cell 21 within a reasonable range.

[0194] In some embodiments, X1 = 1.

[0195] It is understood that in embodiments where the battery compartment 11 contains multiple batteries 2, all batteries 2 in the battery compartment 11 are connected in series.

[0196] In this embodiment, the positive electrode material of the battery cell 21 includes lithium phosphate, and X2 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18.

[0197] In some embodiments, X2 = 1, 2000Ah ≤ C ≤ 11000Ah.

[0198] In this embodiment, X1 = 1, X2 = 1, and C can be any point value or a range value between any two of the following: 2000Ah, 3000Ah, 4000Ah, 5000Ah, 6000Ah, 7000Ah, 8000Ah, 9000Ah, 10000Ah, and 11000Ah.

[0199] In this embodiment, when the positive electrode material of the battery cell 21 includes lithium phosphate, and the number of parallel connections X1 of the batteries 2 in the battery compartment 11 and the number of parallel connections X2 of the battery cells 21 of the batteries 2 are both 1, the capacity of the battery cell 21 is set in the range of 2000Ah to 11000Ah, which can meet both the power matching requirements of the energy storage device 10 and the voltage requirements of the energy storage device 10.

[0200] In some embodiments, 2500Ah≤C≤6000Ah.

[0201] In this embodiment, X1 = 1 and X2 = 1. C can be a point value of any one of 2500Ah, 2800Ah, 3000Ah, 3300Ah, 3500Ah, 3800Ah, 4000Ah, 4300Ah, 4500Ah, 4800Ah, 5000Ah, 5300Ah, 5500Ah, 5800Ah, 6000Ah, or a range value between any two.

[0202] In some embodiments, X2 = 2, 1000Ah ≤ C ≤ 5500Ah.

[0203] In this embodiment, X1 = 1 and X2 = 2. C can be a point value of any one of 1000Ah, 1500Ah, 2000Ah, 2500Ah, 3000Ah, 3500Ah, 4000Ah, 4500Ah, 5000Ah, etc., or a range value between any two.

[0204] When the positive electrode material of the battery cell 21 includes lithium phosphate, the number of parallel connections X1 of the batteries 2 in the battery compartment 11 is 1, and the number of parallel connections X2 of the battery cells 21 of the battery 2 is 2, setting the capacity of the battery cell 21 in the range of 1000Ah to 5500Ah can meet both the power matching requirements of the energy storage device 10 and the voltage requirements of the energy storage device 10.

[0205] In some embodiments, 2000Ah≤C≤4000Ah.

[0206] In this embodiment, X1 = 1 and X2 = 2. C can be a point value of any one of 2000Ah, 2100Ah, 2200Ah, 2300Ah, 2400Ah, 2500Ah, 2600Ah, 2700Ah, 2800Ah, 2900Ah, 3000Ah, 3100Ah, 3200Ah, 3300Ah, 3400Ah, 3500Ah, 3600Ah, 3700Ah, 3800Ah, 3900Ah, 4000Ah, or a range value between any two.

[0207] In some embodiments, 2 ≤ X1 ≤ 6.

[0208] In this embodiment, X1 can be 2, 3, 4, 5, or 6.

[0209] In this embodiment, the positive electrode material of the battery cell 21 includes lithium phosphate, which controls the number of parallel batteries 2 X1 in the battery compartment 11 within a reasonable range. X1≥2 ensures that the capacity of the battery cell 21 is not too large, reducing the manufacturing difficulty and cost of the battery cell 21. X1≤6 ensures that the number of parallel batteries 2 X1 in the battery compartment 11 is not too large, which is beneficial to improving the space utilization of the battery compartment 11.

[0210] In some embodiments, X1 = 4, X2 = 1, and 500Ah ≤ C ≤ 2600Ah.

[0211] In this embodiment, C can be a point value of any one of 500Ah, 800Ah, 1000Ah, 1300Ah, 1500Ah, 1800Ah, 2000Ah, 2300Ah, 2500Ah, 2600Ah, or a range value between any two.

[0212] In this embodiment, when the positive electrode material of the battery cell 21 includes lithium phosphate and X1 = 4 and X2 = 1, the capacity of the battery cell 21 is set in the range of 500Ah to 2600Ah, which can meet both the power matching requirements and the voltage requirements of the energy storage device 10.

[0213] In some embodiments, 800Ah≤C≤1500Ah.

[0214] In this embodiment, X1 = 4, X2 = 1, and C can be any point value of 800Ah, 900Ah, 1000Ah, 1100Ah, 1200Ah, 1300Ah, 1400Ah, 1500Ah, or any range value between two of them.

[0215] In some embodiments, X1 = 4, X2 = 2, and 250Ah ≤ C ≤ 1300Ah.

[0216] In this embodiment, C can be a point value of any one of 250Ah, 300Ah, 400Ah, 500Ah, 600Ah, 700Ah, 800Ah, 900Ah, 1000Ah, 1100Ah, 1200Ah, 1300Ah, or a range value between any two.

[0217] In this embodiment, when the positive electrode material of the battery cell 21 includes lithium phosphate and X1 = 4 and X2 = 2, the capacity of the battery cell 21 is set in the range of 800Ah to 1500Ah, which can meet both the power matching requirements and the voltage requirements of the energy storage device 10.

[0218] In some embodiments, 350Ah≤C≤1000Ah.

[0219] In this embodiment, the positive electrode material of the battery cell 21 includes lithium phosphate, X1=4, X2=2, and C can be any one of 350Ah, 400Ah, 450Ah, 500Ah, 550Ah, 600Ah, 650Ah, 700Ah, 750Ah, 800Ah, 850Ah, 900Ah, 950Ah, 1000Ah, or any range between two values.

[0220] In some embodiments, 500Ah≤C≤700Ah.

[0221] In this embodiment, the positive electrode material of the battery cell 21 includes lithium phosphate, X1=4, X2=2, and C can be any one of 500Ah, 530Ah, 550Ah, 580Ah, 588Ah, 600Ah, 630Ah, 650Ah, 680Ah, 700Ah, etc., or a range of any two.

[0222] In some embodiments, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, 2.8V≤U0≤4.35V, and 210≤Y1*Y2≤530.

[0223] Lithium transition metal oxides include, but are not limited to: lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, and lithium nickel cobalt manganese oxides (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0224] In this embodiment, U0 can be any one of the following values ​​or a range between any two: 2.8V, 2.9V, 3V, 3.1V, 3.2V, 3.3V, 3.4V, 3.5V, 3.6V, 3.7V, 3.8V, 3.9V, 4V, 4.1V, 4.2V, 4.3V, 4.35V, etc. Y1*Y2 can be any one of the following values ​​or a range between any two: 210, 224, 240, 250, 256, 280, 288, 300, 304, 320, 336, 360, 384, 400, 416, 440, 468, 480, 496, 512, 530, etc.

[0225] In this embodiment, when the positive electrode material of the battery cell 21 includes lithium transition metal oxide, 2.8V≤U0≤4.35V and 210≤Y1*Y2≤530, the voltage of the energy storage converter 20 can be controlled within a reasonable range. This ensures that the voltage of the energy storage device 10 is not too low, allowing the energy storage device 10 to be compatible with the energy storage converter 20, which has a higher operating voltage, while also preventing the voltage of the energy storage device 10 from being too high. This reduces the requirements for the operating voltage of the energy storage converter 20 and lowers production costs.

[0226] In some embodiments, 3.5*10 6 W≤P≤7.5*10 6 W, M = A, 1 ≤ X1 * X2 ≤ 18.

[0227] In this embodiment, P can be 3.5*10 6 W, 3.75*10 6 W, 4*10 6 W, 4.2*10 6 W, 4.5*10 6 W, 4.9*10 6 W, 5*10 6 W, 5.2*10 6 W, 5.5*10 6 W, 5.8*10 6 W, 6*10 6 W, 6.2*10 6 W, 6.8*10 6 W, 7*10 6 W, 7.2*10 6 W, 7.5*10 6 The value of any one of W or any range between two of them. X1*X2 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18.

[0228] In this embodiment, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, 3.5*10 6 W≤P≤7.5*10 6 When W and M = A, X1*X2 can be set in the range of 1 to 18 to control the capacity of the battery cell 21 within a reasonable range.

[0229] In some embodiments, X1 = 1.

[0230] In this embodiment, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, and X2 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18.

[0231] In some embodiments, X2 = 1, 1500Ah ≤ C ≤ 13400Ah.

[0232] In this embodiment, X1 = 1, X2 = 1, and C can be any point value or a range value between any two of the following: 1500Ah, 1800Ah, 2000Ah, 3000Ah, 4000Ah, 5000Ah, 6000Ah, 7000Ah, 8000Ah, 9000Ah, 10000Ah, 11000Ah, 12000Ah, 13000Ah, and 13400Ah.

[0233] When the positive electrode material of the battery cell 21 includes lithium transition metal oxide, and the number of parallel connections X1 of the battery 2 in the battery compartment 11 and the number of parallel connections X2 of the battery cells 21 of the battery 2 are both 1, setting the capacity of the battery cell 21 in the range of 1500Ah to 13400Ah Ah can satisfy both the power matching requirements of the energy storage device 10 and the voltage requirements of the energy storage device 10.

[0234] In some embodiments, 3000Ah≤C≤7000Ah.

[0235] In this embodiment, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, X1 = 1, and X2 = 1. C can be any point value or a range between any two of the following: 3000Ah, 3300Ah, 3500Ah, 3800Ah, 4000Ah, 4300Ah, 4500Ah, 4800Ah, 5000Ah, 5300Ah, 5500Ah, 5800Ah, 6000Ah, 6300Ah, 6500Ah, 6800Ah, and 7000Ah.

[0236] In some embodiments, X2 = 2, 750Ah ≤ C ≤ 6670Ah.

[0237] In this embodiment, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, X1 = 1, and X2 = 2. C can be any point value or a range between any two of the following: 750Ah, 850Ah, 1000Ah, 1500Ah, 2000Ah, 2500Ah, 3000Ah, 3500Ah, 4000Ah, 4500Ah, 5000Ah, 5500Ah, 6000Ah, 6500Ah, and 6670Ah.

[0238] When the positive electrode material of the battery cell 21 includes lithium transition metal oxide, the number of parallel connections X1 of the batteries 2 in the battery compartment 11 is 1, and the number of parallel connections X2 of the battery cells 21 of the battery 2 is 2, setting the capacity of the battery cell 21 in the range of 750Ah to 6670Ah can meet both the power matching requirements of the energy storage device 10 and the voltage requirements of the energy storage device 10.

[0239] In some embodiments, 1800Ah≤C≤4000Ah.

[0240] In this embodiment, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, X1 = 1, and X2 = 2. C can be any point value or a range between any two of the following: 1800Ah, 1900Ah, 2000Ah, 2100Ah, 2200Ah, 2300Ah, 2400Ah, 2500Ah, 2600Ah, 2700Ah, 2800Ah, 2900Ah, 3000Ah, 3100Ah, 3200Ah, 3300Ah, 3400Ah, 3500Ah, 3600Ah, 3700Ah, 3800Ah, 3900Ah, and 4000Ah.

[0241] In some embodiments, 2 ≤ X1 ≤ 6.

[0242] In this embodiment, X1 can be 2, 3, 4, 5, or 6.

[0243] In this embodiment, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, which controls the number of batteries 2 connected in parallel X1 in the battery compartment 11 within a reasonable range. This ensures that the capacity of the battery cell 21 is not too large, reducing the manufacturing difficulty and cost of the battery cell 21, and also ensures that the number of batteries 2 connected in parallel X1 in the battery compartment 11 is not too large, which is beneficial to improving the space utilization of the battery compartment 11.

[0244] In some embodiments, X1 = 4, X2 = 1, and 375Ah ≤ C ≤ 3300Ah.

[0245] In this embodiment, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, and C can be any one of 375Ah, 500Ah, 800Ah, 1000Ah, 1300Ah, 1500Ah, 1800Ah, 2000Ah, 2300Ah, 2500Ah, 2600Ah, 2800Ah, 3000Ah, 3150Ah, 3300Ah, etc., or a range of values ​​between any two.

[0246] In this embodiment, when the positive electrode material of the battery cell 21 includes lithium transition metal oxide and X1 = 4 and X2 = 1, the capacity of the battery cell 21 is set in the range of 375Ah to 3300Ah, which can meet both the power matching requirements of the energy storage device 10 and the voltage requirements of the energy storage device 10.

[0247] In some embodiments, 700Ah≤C≤1600Ah.

[0248] In this embodiment, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, X1 = 4, X2 = 1, and C can be any one of 700Ah, 800Ah, 900Ah, 1000Ah, 1100Ah, 1200Ah, 1300Ah, 1400Ah, 1500Ah, 1600Ah, etc., or a range of values ​​between any two.

[0249] In some embodiments, X1 = 4, X2 = 2, and 200Ah ≤ C ≤ 1600Ah.

[0250] In this embodiment, C can be a point value of any one of 200Ah, 300Ah, 400Ah, 500Ah, 600Ah, 700Ah, 800Ah, 900Ah, 1000Ah, 1100Ah, 1200Ah, 1300Ah, 1400Ah, 1500Ah, 1600Ah, or a range value between any two.

[0251] In this embodiment, when the positive electrode material of the battery cell 21 includes lithium transition metal oxide and X1 = 4 and X2 = 2, the capacity of the battery cell 21 is set in the range of 200Ah to 1600Ah, which can meet both the power matching requirements and the voltage requirements of the energy storage device 10.

[0252] In some embodiments, 340Ah≤C≤1050Ah.

[0253] In this embodiment, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, X1=4, X2=2, and C can be any one of 340Ah, 400Ah, 450Ah, 500Ah, 550Ah, 600Ah, 650Ah, 700Ah, 750Ah, 800Ah, 850Ah, 900Ah, 950Ah, 1000Ah, 1050Ah, etc., or a range of values ​​between any two.

[0254] In some embodiments, 490Ah≤C≤720Ah.

[0255] In this embodiment, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, X1=4, X2=2, and C can be any one of 490Ah, 500Ah, 530Ah, 550Ah, 572Ah, 580Ah, 600Ah, 630Ah, 650Ah, 680Ah, 700Ah, 720Ah, or any value between two of them.

[0256] In some embodiments, the battery cell 21 is a sodium-ion battery cell with 1.5V≤U0≤4V and 230≤Y1*Y2≤1000.

[0257] In this embodiment, U0 can be any point value or a range value between any two of the following: 1.5V, 1.6V, 1.7V, 1.8V, 1.9V, 2V, 2.1V, 2.2V, 2.3V, 2.4V, 2.5V, 2.6V, 2.7V, 2.8V, 2.9V, 3V, 3.1V, 3.2V, 3.3V, 3.4V, 3.5V, 3.6V, 3.7V, 3.8V, 3.9V, and 4V. Y1*Y2 can be any point value or a range of values ​​between any two of the following: 230, 240, 250, 256, 280, 288, 300, 304, 320, 336, 360, 384, 400, 416, 440, 468, 480, 496, 512, 530, 560, 600, 640, 680, 720, 760, 800, 840, 880, 920, 960, 1000.

[0258] When the battery cell 21 is a sodium-ion battery cell, 1.5V≤U0≤4V and 230≤Y1*Y2≤1000 can control the voltage of the energy storage converter 20 within a reasonable range. This ensures that the voltage of the energy storage device 10 is not too low, allowing the energy storage device 10 to be compatible with the energy storage converter 20, which has a higher operating voltage. It also ensures that the voltage of the energy storage device 10 is not too high, reducing the requirements for the operating voltage of the energy storage converter 20 and lowering production costs.

[0259] In some embodiments, 3.5*10 6 W≤P≤7.5*10 6 W, M = A, 1 ≤ X1 * X2 ≤ 18.

[0260] In this embodiment, P can be 3.5*10 6 W, 3.75*10 6 W, 4*10 6 W, 4.2*10 6 W, 4.5*10 6 W, 4.9*10 6 W, 5*10 6 W, 5.2*10 6 W, 5.5*10 6 W, 5.8*10 6 W, 6*10 6 W, 6.2*10 6 W, 6.8*10 6 W, 7*10 6 W, 7.2*10 6 W, 7.5*10 6The value of any one of W or any range between two of them. X1*X2 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18.

[0261] Battery cell 21 is a sodium-ion battery cell, 3.5*10 6 W≤P≤7.5*10 6 When W and M = A, X1*X2 can be set in the range of 1 to 18 to control the capacity of the battery cell 21 within a reasonable range.

[0262] In some embodiments, X1 = 1.

[0263] In this embodiment, the battery cell 21 is a sodium-ion battery cell, and X2 can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18.

[0264] In some embodiments, X2 = 1, 1200Ah ≤ C ≤ 18000Ah.

[0265] In this embodiment, X1 = 1, X2 = 1, and C can be any point value or a range value between any two of the following: 1200Ah, 1500Ah, 1800Ah, 2000Ah, 3000Ah, 4000Ah, 5000Ah, 6000Ah, 7000Ah, 8000Ah, 9000Ah, 10000Ah, 11000Ah, 12000Ah, 13000Ah, 14000Ah, 15000Ah, 16000Ah, 17000Ah, and 18000Ah.

[0266] When the battery cell 21 is a sodium-ion battery cell, and the number of parallel connections X1 of the battery 2 in the battery compartment 11 and the number of parallel connections X2 of the battery cells 21 of the battery 2 are both 1, setting the capacity of the battery cell 21 in the range of 1200Ah to 18000Ah can satisfy both the power matching requirements of the energy storage device 10 and the voltage requirements of the energy storage device 10.

[0267] In some embodiments, 2000Ah≤C≤10000Ah.

[0268] In this embodiment, the battery cell 21 is a sodium-ion battery cell, X1 = 1, and X2 = 1. C can be any point value or a range of any two of the following: 2000Ah, 2300Ah, 2500Ah, 2800Ah, 3000Ah, 3300Ah, 3500Ah, 3800Ah, 4000Ah, 4300Ah, 4500Ah, 4800Ah, 5000Ah, 5300Ah, 5500Ah, 5800Ah, 6000Ah, 6300Ah, 6500Ah, 6800Ah, 7000Ah, 8000Ah, 9000Ah, and 10000Ah.

[0269] In some embodiments, X2 = 2, 600Ah ≤ C ≤ 9000Ah.

[0270] In this embodiment, the battery cell 21 is a sodium-ion battery cell, X1 = 1, and X2 = 2. C can be any point value or a range between any two of the following: 600Ah, 650Ah, 700Ah, 750Ah, 850Ah, 1000Ah, 1500Ah, 2000Ah, 2500Ah, 3000Ah, 3500Ah, 4000Ah, 4500Ah, 5000Ah, 5500Ah, 6000Ah, 6500Ah, 7000Ah, 7500Ah, 8000Ah, 8500Ah, and 9000Ah.

[0271] When the battery cell 21 is a sodium-ion battery cell, the number of parallel connections X1 of the batteries 2 in the battery compartment 11 is 1, and the number of parallel connections X2 of the battery cells 21 of the battery 2 is 2, setting the capacity of the battery cell 21 in the range of 600Ah to 9000Ah can meet both the power matching requirements of the energy storage device 10 and the voltage requirements of the energy storage device 10.

[0272] In some embodiments, 1600Ah≤C≤4000Ah.

[0273] In this embodiment, the battery cell 21 is a sodium-ion battery cell, X1 = 1, and X2 = 2. C can be any point value or a range between any two of the following: 1600Ah, 1700Ah, 1800Ah, 1900Ah, 2000Ah, 2100Ah, 2200Ah, 2300Ah, 2400Ah, 2500Ah, 2600Ah, 2700Ah, 2800Ah, 2900Ah, 3000Ah, 3100Ah, 3200Ah, 3300Ah, 3400Ah, 3500Ah, 3600Ah, 3700Ah, 3800Ah, 3900Ah, and 4000Ah.

[0274] In some embodiments, 2 ≤ X1 ≤ 6.

[0275] In this embodiment, X1 can be 2, 3, 4, 5, or 6.

[0276] In this embodiment, the number of parallel batteries X1 in the battery compartment 11 is controlled within a reasonable range, so that the capacity of the battery cell 21 is not too large, reducing the manufacturing difficulty and cost of the battery cell 21, and the number of parallel batteries X1 in the battery compartment 11 is not too large, which is conducive to improving the space utilization of the battery compartment 11.

[0277] In some embodiments, X1 = 4, X2 = 1, and 300Ah ≤ C ≤ 4000Ah.

[0278] In this embodiment, the battery cell 21 is a sodium-ion battery cell, and C can be any one of 300Ah, 375Ah, 400Ah, 500Ah, 800Ah, 1000Ah, 1300Ah, 1500Ah, 1800Ah, 2000Ah, 2300Ah, 2500Ah, 2600Ah, 2800Ah, 3000Ah, 3150Ah, 3300Ah, 3500Ah, 3700Ah, 3900Ah, 4000Ah, or a range of any two.

[0279] When the battery cell 21 is a sodium-ion battery cell and X1 = 4 and X2 = 1, setting the capacity of the battery cell 21 in the range of 300Ah to 4000Ah can satisfy both the power matching requirements and the voltage requirements of the energy storage device 10.

[0280] In some embodiments, 700Ah≤C≤1500Ah.

[0281] In this embodiment, the battery cell 21 is a sodium-ion battery cell, X1 = 4, X2 = 1, and C can be any point value or a range value between any two of 700Ah, 800Ah, 900Ah, 1000Ah, 1100Ah, 1200Ah, 1300Ah, 1400Ah, 1500Ah, etc.

[0282] In some embodiments, X1 = 4, X2 = 2, and 150Ah ≤ C ≤ 1500Ah.

[0283] In this embodiment, C can be a point value of any one of 150Ah, 200Ah, 300Ah, 400Ah, 500Ah, 600Ah, 700Ah, 800Ah, 900Ah, 1000Ah, 1100Ah, 1200Ah, 1300Ah, 1400Ah, 1500Ah, or a range value between any two.

[0284] When the battery cell 21 is a sodium-ion battery cell and X1 = 4 and X2 = 2, setting the capacity of the battery cell 21 in the range of 150Ah to 1500Ah can satisfy both the power matching requirements and the voltage requirements of the energy storage device 10.

[0285] In some embodiments, 350Ah≤C≤1200Ah.

[0286] In this embodiment, the battery cell 21 is a sodium-ion battery cell, X1=4, X2=2, and C can be any one of 350Ah, 400Ah, 450Ah, 500Ah, 550Ah, 600Ah, 650Ah, 700Ah, 750Ah, 800Ah, 850Ah, 900Ah, 950Ah, 1000Ah, 1050Ah, 1100Ah, 1200Ah, or a range of any two.

[0287] In some embodiments, 400Ah≤C≤650Ah.

[0288] In this embodiment, the battery cell 21 is a sodium-ion battery cell, X1=4, X2=2, and C can be any one of 400Ah, 420Ah, 450Ah, 470Ah, 490Ah, 500Ah, 506Ah, 530Ah, 550Ah, 580Ah, 600Ah, 630Ah, 650Ah, etc., or a range of values ​​between any two.

[0289] In some embodiments, combined with Figure 3 and Figure 8 X1 first battery packs 2a are arranged along the length X of the casing.

[0290] In this embodiment, the battery compartment 11 contains N1 batteries 2, which are formed by X1 first battery packs 2a connected in parallel, and each first battery pack 2a is formed by Y1 batteries 2 connected in series. As an example, 2 ≤ X1 ≤ 6.

[0291] It should be noted that, regardless of whether the battery cell 21 is a sodium-ion battery 2, or whether the positive electrode material of the battery cell 21 includes lithium phosphate, or whether the positive electrode material of the battery cell 21 includes lithium transition metal oxide, it can be X1 first battery packs 2a arranged along the length X of the casing.

[0292] In this embodiment, X1 first battery packs 2a are arranged along the length direction X of the housing. If X is set between 2 and 6, the space of the battery compartment 11 along the length direction X of the housing can be fully utilized. The layout is reasonable and helps to improve the space utilization rate of the battery compartment 11.

[0293] In some embodiments, please refer to Figures 12-14 , Figure 12 Schematic diagrams of the structure of the energy storage device 10 provided in other embodiments of this application;

[0294] Figure 13 for Figure 12 The diagram shows the structure of box 1. Figure 14 for Figure 12 The energy storage device 10 shown is a BB cross-sectional view. The battery compartment 11 includes a plurality of sub-compartments 111, which are arranged along the length direction X of the casing. Each sub-compartment 111 contains a first battery pack 2a along the length direction X of the casing.

[0295] The first battery pack 2a in each sub-compartment 111 can also be called a battery cluster, and the number of battery clusters can be equal to the number of sub-compartments 111. During installation, Y1 batteries 2 can be housed in the sub-compartment 111 and connected in series to form a first battery pack 2a.

[0296] Sub-compartments 111 can be two, three, four, five, six, or more. Adjacent sub-compartments 111 can be separated by a partition 112. The partition 112 can be a partition plate between the two sub-compartments 111, or a partition beam between them. The partition beam can extend along the height direction Z of the container. When the partition 112 is a partition beam between two adjacent sub-compartments 111, multiple partition beams can be provided, and these multiple partition beams can be arranged at intervals along the width direction Y of the container.

[0297] Sub-compartment 111 can have various shapes, such as cylindrical or prismatic. Prismatic shapes can be triangular, square, pentagonal, hexagonal, etc. Along the length X of the housing, sub-compartment 111 can hold one or more batteries 2; along the height Z of the housing, sub-compartment 111 can hold one or more batteries 2; and along the width of the housing 1, sub-compartment 111 can hold one or more batteries 2.

[0298] In this embodiment, the battery compartment 11 is divided into multiple sub-compartments 111, each of which can accommodate the first battery pack 2a. This allows the first battery pack 2a to be accommodated more regularly within the battery compartment 11, making it easier to install the battery 2 in the first battery pack 2a.

[0299] In some embodiments, please continue to refer to Figures 12-14Along the height direction Z of the box, the battery compartment 11 can only hold one first battery pack 2a. Y1 batteries 2 in each first battery pack 2a are arranged along the height direction Z of the box, and 2≤Y1≤10.

[0300] Y1 can be 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0301] It is understood that all the batteries 2 in the first battery pack 2a are arranged along the height direction Z of the housing. In an embodiment where the sub-compartment 111 accommodates only one first battery pack 2a, it is understood that along the height direction Z of the housing, the sub-compartment 111 accommodates multiple batteries 2, which are connected in series. As an example, along the width direction Y of the housing, the sub-compartment 111 accommodates only one battery 2; along the length direction X of the housing, the sub-compartment 111 accommodates only one battery 2.

[0302] As an example, along the length X of the housing, each sub-compartment 111 has a support member 113 on both sides. Along the height Z of the housing, the support member 113 is located at the bottom of the battery 2. The support member 113 is used to support the battery 2. The support member 113 can be installed on the compartment wall of the battery compartment 11 and the partition 112. The arrangement of the support member 113 improves the stability of each battery 2 within the sub-compartment 111; furthermore, it ensures that two adjacent batteries 2 within the sub-compartment 111 maintain a certain distance along the height Z of the housing, minimizing the impact on adjacent batteries 2 when installing or removing one battery 2.

[0303] In an embodiment where the housing 1 has an electrical compartment 14 and a main control compartment 13, the main control unit in the main control compartment 13 can realize high-voltage control and communication of the first battery pack 2a (battery cluster), and the current combining unit in the electrical compartment 14 can realize the parallel current combining of multiple first battery packs 2a, and realize the safe connection between multiple first battery packs 2a and the DC side of the energy storage converter 20.

[0304] In this embodiment, all the batteries 2 in the first battery pack 2a are arranged along the height direction Z of the housing, which facilitates the series connection of all the batteries 2 in the first battery pack 2a. Y1 is set between 2 and 10 to prevent it from becoming too large. The number of batteries 2 arranged along the height direction Z in the battery compartment 11 is not too large, which helps to improve the space utilization of the battery compartment 11.

[0305] In some embodiments, please refer to Figures 15-18 , Figure 15 Axonometric view of a battery cell 21 provided in some embodiments of this application; Figure 16 for Figure 15 An exploded view of the battery cell 21 shown; Figure 17 for Figure 15 The exploded cross-sectional view of the battery cell 21 shown is taken along the UW plane. Figure 18for Figure 15 The image shows an exploded cross-sectional view of the battery cell 21 cut along the VW plane. This application also provides a battery cell 21, which includes a housing 211 and at least one electrode assembly 213 housed within the housing 211. The housing 211 is a right parallelepiped, with a dimension W1 in a first direction U, a dimension T1 in a second direction V, and a dimension K1 in a third direction W. One of the three directions U, V, and W is parallel to the length direction X of the housing, another is parallel to the width direction Y, and the third is parallel to the height direction Z. The housing 211 includes a first wall 2113 and a second wall 2113 disposed opposite to each other along the first direction U. 114. The third wall 2115 and the fourth wall 2116 are arranged opposite each other along the second direction V, and the fifth wall 2117 and the sixth wall 2118 are arranged opposite each other along the third direction W. The sum of the thicknesses of the first wall 2113 and the second wall 2114 is a, the sum of the thicknesses of the third wall 2115 and the fourth wall 2116 is b, and the sum of the thicknesses of the fifth wall 2117 and the sixth wall 2118 is c, satisfying: (W1-a)*(T1-b)*(K1-c) / (W1*T1*K1)≥90%.

[0306] There may be one or more electrode components 213 inside the housing 211. If there are multiple electrode components 213 inside the housing 211, the multiple electrode components 213 may be connected in parallel.

[0307] The outer shell 211 is in the shape of a right parallelepiped, which can be a cuboid, cube, etc. Of the six walls of the outer shell 211, four walls can form the outer shell 211, and the other two walls can be end caps 2112; alternatively, five walls can form the outer shell 211, and the remaining wall can be an end cap 2112. The dimensions of the outer shell 211 in the first direction U, the dimensions of the outer shell 211 in the second direction V, the dimensions of the outer shell 211 in the third direction W, the thicknesses of the first wall 2113, the second wall 2114, the third wall 2115, the fourth wall 2116, the fifth wall 2117, and the sixth wall 2118 can all be measured using vernier calipers.

[0308] As an example, the first wall 2113, the second wall 2114, the third wall 2115, the fourth wall 2116, the fifth wall 2117, and the sixth wall 2118 are all aluminum alloys. The aluminum alloys comprise the following components by mass percentage: aluminum ≥ 96.7%, copper ≤ 0.05% ≤ 0.2%, iron ≤ 0.7%, manganese ≤ 1.5%, silicon ≤ 0.6%, zinc ≤ 0.1%, other individual element components ≤ 0.05%, and total other element components ≤ 0.15%.

[0309] As an example, the first direction U is the length direction of the outer casing 211 of the battery cell 21, the second direction V is the width direction of the outer casing 211 of the battery cell 21, and the third direction W is the height direction of the outer casing 211 of the battery cell 21. It can be understood that W1 is the length of the outer casing 211 of the battery cell 21, T1 is the width of the outer casing 211 of the battery cell 21, and K1 is the height of the outer casing 211 of the battery cell 21.

[0310] (W1-a)*(T1-b)*(K1-c) / (W1*T1*K1) can be a point value of any one of 90%, 90.5%, 91%, 91.5%, 92%, 92.5%, 93%, 93.5%, 94%, 94.5%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, or a range between any two.

[0311] Where (W1-a)*(T1-b)*(K1-c) can be understood as the volume of the internal space of the outer shell 211, that is, the volume of the space enclosed by the inner surface of the outer shell 211. W1*T1*K1 is the volume of the outer shell 211.

[0312] If the outer surfaces of the six walls of the outer shell 211 are all planar, then W1, T1, and K1 are measured with each outer surface of the wall as a reference. For example, if the outer surfaces of the fifth wall 2117 and the sixth wall 2118 are both planar, then K1 is the distance between the outer surfaces of the fifth wall 2117 and the sixth wall 2118 along the third direction W.

[0313] If a protrusion or recess is formed on the outer surface of one of the walls of the outer casing 211, W1, T1, and K1 are measured with reference to the planar area of ​​that outer surface (i.e., the area other than the protrusion or recess). For example, if the outer surface of the fifth wall 2117 is planar and the outer surface of the sixth wall 2118 has a first protrusion (e.g., if the sixth wall 2118 is an end cap 2112, and the protrusion formed on the end cap 2112 is the first protrusion), then K1 is the distance along the third direction W between the planar area of ​​the outer surface of the sixth wall 2118 excluding the first protrusion and the outer surface of the fifth wall 2117. If the outer surface of the sixth wall 2118 has a first protrusion and the outer surface of the fifth wall 2117 has a second protrusion, then K1 is the distance along the third direction W between the planar area of ​​the outer surface of the fifth wall 2117 excluding the second protrusion and the planar area of ​​the outer surface of the sixth wall 2118 excluding the first protrusion.

[0314] If all six walls of the outer casing 211 are of uniform thickness, the thickness of the wall can be obtained by measuring the distance between its outer and inner surfaces from any position on each wall. If one wall of the outer casing 211 is of non-uniform thickness, the thickness of the wall is obtained by measuring the distance between its outer and inner surfaces from the point of maximum thickness. In other words, if the thickness of a wall is non-uniform, the maximum thickness of that wall is used to calculate a, b, or c.

[0315] In such a battery cell 21, the ratio of the volume of the internal space of the outer shell 211 to the volume of the outer shell 211 is more than 90%, which makes the internal space of the outer shell 211 account for a large proportion. The space that the outer shell 211 can use to accommodate the electrode assembly 213 is increased. Under the same chemical system, the volumetric energy density of the battery cell 21 can be improved.

[0316] The following is a detailed explanation using specific experimental data:

[0317] In the experiment, the battery cell 21 is a square-shell battery cell 21. The shell 2111 of the outer shell 211 is a hollow structure with one end open. The end cap 2112 in the battery cell 21 is one.

[0318] Table 2

[0319]

[0320]

[0321] According to Table 2 above, comparing Examples 10-13 and Comparative Example 2, it can be seen that when the cathode material of battery cell 21 includes lithium phosphate, (W1-a)*(T1-b)*(K1-c) / (W1*T1*K1)≥90%, the volumetric energy density of battery cell 21 can be effectively improved. Comparing Examples 14-17 and Comparative Example 3, it can be seen that when the cathode material of battery cell 21 includes lithium transition metal oxide, (W1-a)*(T1-b)*(K1-c) / (W1*T1*K1)≥90%, the volumetric energy density of battery cell 21 can be effectively improved. Comparing Examples 18-21 and Comparative Example 4, it can be seen that when battery cell 21 is a sodium-ion battery cell, (W1-a)*(T1-b)*(K1-c) / (W1*T1*K1)≥90%, the volumetric energy density of battery cell 21 can be effectively improved.

[0322] In some embodiments, (W1-a) / W1≥97%, (T1-b) / T1≥96.5%, and (K1-c) / K1≥96.5%.

[0323] By setting the ratio of W1-a to W1 to 97% or higher, the length of the internal space of the casing 211 is increased while the length of the battery cell 21 remains unchanged, thereby accommodating a longer electrode assembly 213; under the same chemical material system, the volumetric energy density of the battery cell 21 can be improved. (W1-a) / W1 can be a point value of any one of 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, etc., or a range between any two.

[0324] By setting the ratio of T1-b to T1 to 96.5% or higher, the width of the internal space of the casing 211 is increased while the width of the battery cell 21 remains unchanged, thereby accommodating a wider electrode assembly 213; under the same chemical material system, the volumetric energy density of the battery cell 21 can be improved. (T1-b) / T1 can be a point value of any one of 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, etc., or a range between any two.

[0325] By setting the ratio of K1-c to K1 to 96.5% or higher, the height of the internal space of the casing 211 is increased while the height of the battery cell 21 remains unchanged, thereby accommodating a taller electrode assembly 213; under the same chemical material system, the volumetric energy density of the battery cell 21 can be improved. (K1-c) / K1 can be a point value of any one of 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.5%, etc., or a range between any two.

[0326] In some embodiments, please continue to refer to Figures 15-18 The outer casing 211 includes a housing 2111 and an end cap 2112. The housing 2111 has an opening, and the end cap 2112 closes to the opening. The housing 2111 includes an integrally formed first wall 2113, a second wall 2114, a third wall 2115, a fourth wall 2116, and a fifth wall 2117, and the end cap 2112 is a sixth wall 2118.

[0327] In this embodiment, the housing 2111 is a hollow structure with an opening at one end, and there is one end cap 2112 in the housing 211. The end cap 2112 is separately disposed from the housing 2111 and connected thereto. The end cap 2112 and the housing 2111 can be welded or rolled together, etc.

[0328] When assembling battery 2, the electrode terminal 212 can be installed on the end cover 2112 first, then the electrode assembly 213 can be housed in the housing 2111, and then the end cover 2112 can be closed on the opening of the housing 2111. This can reduce the difficulty of installing the electrode assembly 213 in the housing 211 and the difficulty of installing the electrode terminal 212 in the housing 211.

[0329] In some embodiments, please continue to refer to Figure 17 and Figure 18 The thickness of the first wall 2113 and the second wall 2114 is a1, 2*a1=a; the thickness of the third wall 2115 and the fourth wall 2116 is b1, 2*b1=b; the thickness of the fifth wall 2117 is c1, and the thickness of the sixth wall 2118 is c2, c2>c1, c1>a1, c1>b1. 0.5mm≤a1≤1.5mm, 0.5≤b1≤1.5mm, 1.0mm≤c1≤2.5mm, 1.5mm≤c2≤4mm.

[0330] In order to reduce the possibility of interference between the electrode assembly 213 and the housing 2111 during the installation process and to reduce the risk of damage to the electrode assembly 213, a certain assembly gap (i.e., housing gap) will be left for the electrode assembly 213 when designing the housing 2111. This assembly gap can be 0.8-2mm.

[0331] In addition, in order to reduce the possibility of internal short circuits in the battery cell 21, an insulating component can be installed inside the casing 211. However, the insulating component will inevitably occupy part of the internal space of the casing 211, thereby reducing the space available for the electrode assembly 213 and the electrolyte.

[0332] In some embodiments, the battery cell 21 may further include a first insulating member 214 and a second insulating member 215. The first insulating member 214 is disposed between the fifth wall 2117 and the electrode assembly 213 and abuts against the fifth wall 2117. The second insulating member 215 is disposed between the sixth wall 2118 and the electrode assembly 213 and abuts against the sixth wall 2118. The maximum dimension of the first insulating member 214 in the third direction W is e1, and the maximum dimension of the second insulating member 215 in the third direction W is e2, satisfying: (W1-a-1.6mm)*(T1-b-1.6mm)*(K1-c-e1-e2) / (W1*T1*K1)≥88%, 0.3mm≤e1≤1.2mm, and 2mm≤e2≤10mm.

[0333] (W1-a-1.6mm)*(T1-b-1.6mm)*(K1-c-e1-e2) / (W1*T1*K1) can be a point value of any one of 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or a range between any two.

[0334] e1 can be a point value or a range value between any two of the following: 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm.

[0335] e2 can be a point value of any one of 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc., or a range value between any two.

[0336] In this embodiment, W1-a-1.6mm means that when the assembly gap between the electrode assembly 213 and the housing 2111 is 0.8mm, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the first direction U. T1-b-1.6mm means that when the assembly gap between the electrode assembly 213 and the housing 2111 is 0.8mm, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the second direction V. K1-c-e1-e2 means that when a first insulating member 214 abutting against the fifth wall 2117 is provided between the fifth wall 2117 and the electrode assembly 213, and a second insulating member 215 abutting against the sixth wall 2118 is provided between the sixth wall 2118 and the electrode assembly 213, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the third direction W. The first insulating member 214 can be a bottom plate, and the second insulating member 215 can be a lower plastic.

[0337] In this embodiment, (W1-a-1.6mm)*(T1-b-1.6mm)*(K1-c-e1-e2) / (W1*T1*K1)≥88%, which increases the space left inside the outer casing 211 for the electrode assembly 213, allowing for a larger electrode assembly 213 to be accommodated, thereby further improving the volumetric energy density of the battery cell 21.

[0338] In some embodiments, the battery cell 21 may further include a first insulating member 214 and a second insulating member 215. The first insulating member 214 is disposed between the fifth wall 2117 and the electrode assembly 213 and abuts against the fifth wall 2117. The second insulating member 215 is disposed between the sixth wall 2118 and the electrode assembly 213 and abuts against the sixth wall 2118. The maximum dimension of the first insulating member 214 in the third direction W is e1, and the maximum dimension of the second insulating member 215 in the third direction W is e2, satisfying: (W1-a-4mm)*(T1-b-4mm)*(K1-c-e1-e2) / (W1*T1*K1)≥85%, 0.3mm≤e1≤1.2mm, and 2mm≤e2≤10mm.

[0339] (W1-a-4mm)*(T1-b-4mm)*(K1-c-e1-e2) / (W1*T1*K1) can be a point value or a range between any two of the following: 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%.

[0340] e1 can be a point value or a range value between any two of the following: 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm.

[0341] e2 can be a point value of any one of 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc., or a range value between any two.

[0342] In this embodiment, W1-a-4mm means that when the assembly gap between the electrode assembly 213 and the housing 2111 is 2mm, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the first direction U. T1-b-4mm means that when the assembly gap between the electrode assembly 213 and the housing 2111 is 2mm, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the second direction V. K1-c-e1-e2 means that when a first insulating member 214 abutting against the fifth wall 2117 is provided between the fifth wall 2117 and the electrode assembly 213, and a second insulating member 215 abutting against the sixth wall 2118 is provided between the sixth wall 2118 and the electrode assembly 213, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the third direction W.

[0343] In this embodiment, (W1-a-4mm)*(T1-b-4mm)*(K1-c-e1-e2) / (W1*T1*K1)≥85%, which increases the space left inside the outer casing 211 for the electrode assembly 213, allowing for a larger electrode assembly 213 to be accommodated, thereby further improving the volumetric energy density of the battery cell 21.

[0344] In some embodiments, W1≥T1, the first direction U is parallel to the length direction X of the box, the second direction V is parallel to the width direction Y of the box, and the third direction W is parallel to the height direction Z of the box.

[0345] As an example, the first direction U is the length direction of the outer casing 211 of the battery cell 21, the second direction V is the width direction of the outer casing 211 of the battery cell 21, and the third direction W is the height direction of the outer casing 211 of the battery cell 21, such that the length direction of the outer casing 211 is parallel to the length direction X of the box, the width direction of the outer casing 211 is parallel to the width direction Y of the box, and the height direction of the outer casing 211 is parallel to the height direction Z of the box.

[0346] When the end cap 2112 is provided at only one end of the housing 2111 and W1≥T1, the end cap 2112 and the fifth wall 2117 of the housing 211 are arranged opposite each other along the height direction Z of the box, the first wall 2113 and the second wall 2114 of the housing 211 are arranged opposite each other along the length direction X of the box, and the third wall 2115 and the fourth wall 2116 of the housing 211 are arranged opposite each other along the width direction Y of the box. This is beneficial to increase the volume ratio of all battery cells 21 in the battery compartment 11.

[0347] In some embodiments, please refer to Figures 19-22 , Figure 19 Axonometric view of a battery cell 21 provided in other embodiments of this application; Figure 20 for Figure 19 An exploded view of the battery cell 21 shown; Figure 21 for Figure 19 The exploded cross-sectional view of the battery cell 21 shown is taken along the UW plane. Figure 22 for Figure 19 The exploded cross-sectional view of the battery cell 21 shown is taken along the VW plane. The housing 211 includes a shell 2111 and two end caps 2112. The shell 2111 has two openings disposed opposite each other along a third direction W, and the two end caps 2112 respectively cover the two openings. The shell 2111 includes an integrally formed first wall 2113, a second wall 2114, a third wall 2115 and a fourth wall 2116, and the two end caps 2112 are a fifth wall 2117 and a sixth wall 2118, respectively.

[0348] In this embodiment, the housing 2111 is a hollow structure with openings at both ends, and there are two end caps 2112 in the housing 211, which respectively close the openings at both ends of the housing 2111.

[0349] In some embodiments, please continue to refer to Figure 21 and Figure 22The thickness of the first wall 2113 and the thickness of the second wall 2114 are both a1, 2*a1=a; the thickness of the third wall 2115 and the thickness of the fourth wall 2116 are both b1, 2*b1=b; the thickness of the fifth wall 2117 and the thickness of the sixth wall 2118 are c1, 2*c1=c, c1>a1, c1>b1. 0.5mm≤a1≤1.5mm, 0.5≤b1≤1.5mm, 1.0mm≤c1≤4mm.

[0350] In order to reduce the possibility of interference between the electrode assembly 213 and the housing 2111 during the installation process and to reduce the risk of damage to the electrode assembly 213, a certain assembly gap (i.e., housing gap) will be left for the electrode assembly 213 when designing the housing 2111. This assembly gap can be 0.8-2mm.

[0351] In addition, in order to reduce the possibility of internal short circuits in the battery cell 21, an insulating component can be installed inside the casing 211. However, the insulating component will inevitably occupy part of the internal space of the casing 211, thereby reducing the space available for the electrode assembly 213 and the electrolyte.

[0352] In some embodiments, the battery cell 21 may further include a third insulating member 216 and a fourth insulating member 217. The third insulating member 216 is disposed between the fifth wall 2117 and the electrode assembly 213 and abuts against the fifth wall 2117. The fourth insulating member 217 is disposed between the sixth wall 2118 and the electrode assembly 213 and abuts against the sixth wall 2118. The maximum dimension of the third insulating member 216 in the third direction W is e3, and the maximum dimension of the fourth insulating member 217 in the third direction W is e4, satisfying: (W1-a-1.6mm)*(T1-b-1.6mm)*(K1-c-e3-e4) / (W1*T1*K1)≥88%, 2mm≤e3≤10mm, and 2mm≤e4≤10mm.

[0353] (W1-a-1.6mm)*(T1-b-1.6mm)*(K1-c-e3-e4) / (W1*T1*K1) can be any point value or a range between any two of the following: 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%.

[0354] e3 can be a point value of any one of 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc., or a range value between any two.

[0355] e4 can be a point value of any one of 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc., or a range value between any two.

[0356] In this embodiment, W1-a-1.6mm means that when the assembly gap between the electrode assembly 213 and the housing 2111 is 0.8mm, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the first direction U. T1-b-1.6mm means that when the assembly gap between the electrode assembly 213 and the housing 2111 is 0.8mm, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the second direction V. K1-c-e3-e4 means that when a third insulating member 216 abutting against the fifth wall 2117 is provided between the fifth wall 2117 and the electrode assembly 213, and a fourth insulating member 217 abutting against the sixth wall 2118 is provided between the sixth wall 2118 and the electrode assembly 213, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the third direction W. Both the third insulating member 216 and the fourth insulating member 217 can be made of plastic.

[0357] In this embodiment, W1-a-1.6mm)*(T1-b-1.6mm)*(K1-c-e3-e4) / (W1*T1*K1)≥88%, which increases the space left inside the outer casing 211 for the electrode assembly 213, allowing for a larger electrode assembly 213 to be accommodated, thereby further improving the volumetric energy density of the battery cell 21.

[0358] In some embodiments, the battery cell 21 may further include a third insulating member 216 and a fourth insulating member 217. The third insulating member 216 is disposed between the fifth wall 2117 and the electrode assembly 213 and abuts against the fifth wall 2117. The fourth insulating member 217 is disposed between the sixth wall 2118 and the electrode assembly 213 and abuts against the sixth wall 2118. The maximum dimension of the third insulating member 216 in the third direction W is e3, and the maximum dimension of the fourth insulating member 217 in the third direction W is e4, satisfying: (W1-a-4mm)*(T1-b-4mm)*(K1-c-e3-e4) / (W1*T1*K1)≥85%, 2mm≤e3≤10mm, and 2mm≤e4≤10mm.

[0359] (W1-a-4mm)*(T1-b-4mm)*(K1-c-e3-e4) / (W1*T1*K1) can be any point value or a range between any two of the following: 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%.

[0360] e3 can be a point value of any one of 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc., or a range value between any two.

[0361] e4 can be a point value of any one of 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc., or a range value between any two.

[0362] In this embodiment, W1-a-4mm means: when the assembly gap between the electrode assembly 213 and the housing 2111 is 2mm, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the first direction U. T1-b-4mm means: when the assembly gap between the electrode assembly 213 and the housing 2111 is 2mm, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the second direction V. K1-c-e3-e4 means: when a third insulating member 216 abutting against the fifth wall 2117 is provided between the fifth wall 2117 and the electrode assembly 213, and a fourth insulating member 217 abutting against the sixth wall 2118 is provided between the sixth wall 2118 and the electrode assembly 213, the maximum size of the internal space of the housing 211 reserved for the electrode assembly 213 along the third direction W.

[0363] In this embodiment, (W1-a-4mm)*(T1-b-4mm)*(K1-c-e3-e4) / (W1*T1*K1)≥85%, which increases the space left inside the outer casing 211 for the electrode assembly 213, allowing for a larger electrode assembly 213 to be accommodated, thereby further improving the volumetric energy density of the battery cell 21.

[0364] In some embodiments, W1≥T1, the first direction U is parallel to the height direction Z of the box, the second direction V is parallel to the width direction Y of the box, and the third direction W is parallel to the length direction X of the box.

[0365] As an example, the first direction U is the length direction of the outer casing 211 of the battery cell 21, the second direction V is the width direction of the outer casing 211 of the battery cell 21, and the third direction W is the height direction of the outer casing 211 of the battery cell 21, such that the length direction of the outer casing 211 is parallel to the height direction Z of the box, the width direction of the outer casing 211 is parallel to the width direction Y of the box, and the height direction of the outer casing 211 is parallel to the length direction X of the box.

[0366] With end caps 2112 provided at both ends of the housing 2111 and W1≥T1, the two end caps 2112 of the housing 211 are arranged along the length direction X of the box, the first wall 2113 and the second wall 2114 of the housing 211 are arranged along the height direction Z of the box, and the third wall 2115 and the fourth wall 2116 of the housing 211 are arranged opposite to each other along the width direction Y of the box, which is beneficial to increasing the volume ratio of all battery cells 21 in the battery compartment 11.

[0367] In some embodiments, 3000cm 3 ≤W1*T1*K1≤40000cm 3 .

[0368] W1*T1*K1 can be 3000cm 3 5000cm 3 8000cm 3 10000cm 3 13000cm 3 15000cm 3 18000cm 3 20000cm 3 23000cm 3 25000cm 3 28000cm 3 30000cm 3 33000cm 3 35000cm 3 38000cm 3 40000cm 3 The point value of any one of them or the range value between any two.

[0369] In this embodiment, W1*T1*K1≥3000cm 3 This ensures that, while maintaining a volume ratio of at least 90% between the internal space and the total volume of the outer shell 211, the wall thickness of the outer shell 211 is not too small, thus meeting the structural strength requirements for the outer shell 211; W1*T1*K1≤40000cm 3 This allows the capacity and current of the battery cell 21 to be controlled within a suitable range, reducing the risk of damage to overcurrent components in the circuit.

[0370] In some embodiments, 3200cm 3 ≤W1*T1*K1≤32000cm 3 .

[0371] In this embodiment, W1*T1*K1 can be 3200cm 3 3500cm 34200cm 3 5000cm 3 6000cm 3 7000cm 3 8000cm 3 9000cm 3 10000cm 3 11000cm 3 12000cm 3 13000cm 3 14000cm 3 15000cm 3 16000cm 3 17000cm 3 18000cm 3 19000cm 3 20000cm 3 21000cm 3 22000cm 3 23000cm 3 24000cm 3 25000cm 3 26000cm 3 27000cm 3 28000cm 3 29000cm 3 30000cm 3 31000cm 3 32000cm 3 The point value of any one of them or the range value between any two.

[0372] In this embodiment, 3200cm 3 ≤W1*T1*K1≤32000cm 3 This design balances the structural strength of the casing 211 with the heat generation requirements of the battery cell 21, further improving the structural strength of the casing 211 and reducing the risk of damage to overcurrent components in the circuit.

[0373] In some embodiments, 3720cm 3 ≤W1*T1*K1≤12500cm 3 .

[0374] In this embodiment, W1*T1*K1 can be 3720cm 3 3900cm 3 4200cm 3 4600cm 3 4800cm 35000cm 3 5200cm 3 5800cm 3 6000cm 3 6200cm 3 6800cm 3 7000cm 3 7200cm 3 7800cm 3 8000cm 3 8200cm 3 8800cm 3 9000cm 3 9200cm 3 9800cm 3 10000cm 3 10200cm 3 10800cm 3 11000cm 3 11200cm 3 11800cm 3 12000cm 3 12500cm 3 The point value of any one of them or the range value between any two.

[0375] In some embodiments, 4000cm 3 ≤W1*T1*K1≤6000cm 3 .

[0376] In this embodiment, it can be 4000cm 3 4100cm 3 4200cm 3 4300cm 3 4400cm 3 4500cm 3 4600cm 3 4700cm 3 4800cm 3 4900cm 3 5000cm 3 5100cm 3 5200cm 3 5300cm 3 5400cm 3 5500cm 3 5600cm 3 5700cm 3 5800cm 3 5900cm3 6000cm 3 The point value of any one of them or the range value between any two.

[0377] In some embodiments, the positive electrode material of the battery cell 21 includes lithium phosphate, satisfying: C≥350Ah, C / ((W1-a)*(T1-b)*(K1-c))≥118Ah / L.

[0378] When the positive electrode material of the battery cell 21 includes lithium phosphate and C≥350Ah, setting C / ((W1-a)*(T1-b)*(K1-c)) above 118Ah / L can increase the volume ratio of the internal space of the outer shell 211 of the battery cell 21, which is beneficial to achieving a ratio of the internal space volume of the outer shell 211 to the volume of the outer shell 211 of the battery cell 21 above 90%.

[0379] In some embodiments, the positive electrode material of the battery cell 21 includes lithium transition metal oxide, satisfying: C≥650Ah, C / ((W1-a)*(T1-b)*(K1-c))≥190Ah / L.

[0380] When the cathode material of the battery cell 21 includes lithium transition metal oxide and C≥650Ah, setting C / ((W1-a)*(T1-b)*(K1-c)) to above 190Ah / L can increase the volume ratio of the internal space of the casing 211 of the battery cell 21, which is beneficial to achieving a volume ratio of the internal space of the casing 211 to the volume of the casing 211 of the battery cell 21 to above 90%.

[0381] In some embodiments, the battery cell 21 is a sodium-ion battery cell that satisfies: C≥260Ah, C / ((W1-a)*(T1-b)*(K1-c))≥87Ah / L.

[0382] When the battery cell 21 is a sodium-ion battery cell and C≥260Ah, setting C / ((W1-a)*(T1-b)*(K1-c)) to above 87Ah / L can increase the volume ratio of the internal space of the battery cell 21's casing 211, which is beneficial to achieving a ratio of the internal space volume of the battery cell 21's casing 211 to the volume of the casing 211 to above 90%.

[0383] Furthermore, this application provides an energy storage system 100, including an energy storage converter 20 and M energy storage devices 10 provided in any of the above embodiments, wherein the energy storage devices 10 are electrically connected to the energy storage converter 20.

[0384] Where M is a positive integer, and M can be 1, 2, 3, 4, 5, 6, 7, 8, etc.

[0385] In some embodiments, M = 2, A = 2; or, M = 4, A = 4; or, M = 8, A = 8.

[0386] Furthermore, this application embodiment also provides an energy storage device 10, which is electrically connected to an energy storage converter 20. The energy storage converter 20 can cooperate with M energy storage devices 10, where M is a positive integer. The rated output power of the energy storage converter 20 is P (in W), the energy of the energy storage device 10 is Q (in Wh), and the time for the energy storage device 10 to discharge from a fully charged state to a fully discharged state is A (in hours). The energy storage device 10 includes a housing 1 and multiple batteries 2. The housing 1 includes a battery compartment 11, in which the multiple batteries 2 are housed. Each battery 2 includes a housing 1 and multiple battery cells 21 housed within the housing 1. The capacity of each battery cell 21 is C (in Ah), and the plateau voltage of each battery cell 21 is U0 (in V). The battery compartment 11 contains N1 batteries 2, which are formed by X1 parallel-connected first battery packs 2a. Each first battery pack 2a is formed by Y1 batteries 2 connected in series, where N1 = X1 * Y1. Each battery 2 includes N2 individual battery cells 21, which are formed by Y2 series-connected second battery cell groups 21b. Each second battery cell group 21b is formed by X2 battery cells 21 connected in parallel, where N2 = X2 * Y2, and Q = N1 * N2 * C * U0. The maximum operating voltage on the DC side of the energy storage converter 20 is U1, and the minimum operating voltage on the DC side of the energy storage converter 20 is U2, where U2 < U0 * Y1 * Y2 < U1.

[0387] Among them, the positive electrode material of the battery cell 21 includes lithium iron phosphate, P=4900000W, M=A=4, U1=1500V, U2=900V, C=530Ah, U0=3.23, X1=4, Y1=8, X2=2, Y2=52, P / (M*Q / A)=P / (M*X1*Y1*X2*Y2*C*U0 / A)=0.86.

[0388] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0389] The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit this application. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An energy storage device for electrically connecting an energy storage converter, characterized by, The energy storage device includes a box body and at least one battery, the box body includes a battery compartment, the battery compartment contains N1 batteries, N1 batteries are formed by X1 first battery groups connected in parallel, each first battery group is formed by Y1 batteries connected in series; or, N1 batteries are formed by Y1 second battery groups connected in series, each second battery group is formed by X1 batteries connected in parallel, and satisfy: N1≥1, X1≥1, Y1≥1, N1=X1*Y1; the battery includes N2 battery monomers, N2 battery monomers are formed by X2 first battery monomer groups connected in parallel, each first battery monomer group is formed by Y2 battery monomers connected in series; or, N2 battery monomers are formed by Y2 second battery monomer groups connected in series, each second battery monomer group is formed by X2 battery monomers connected in parallel, and satisfy: N2≥1, X2≥1, Y2≥1, N2=X2*Y2; the capacity of the battery monomer is C, the unit is Ah, the platform voltage of the battery monomer is U0, the unit is V, the total number of the battery monomers in the battery compartment is N, the energy of the energy storage device is Q, the unit is Wh, Q=N*C*U0, N=N1*N2; The energy storage converter can be used in cooperation with M energy storage devices, M is a positive integer, the rated output power of the energy storage converter is P, the unit is W, the time length of discharging the energy storage device from full charge state to full discharge state is A, the unit is h, the maximum working voltage of the direct current side of the energy storage converter is U1, the minimum working voltage of the direct current side of the energy storage converter is U2, and satisfy: 0.7≤P / (M*Q / A)≤0.99, U2 2. The energy storage device of claim 1, wherein, 0.75≤P / (M*Q / A)≤0.

95.

3. The energy storage device of claim 2, wherein, 0.85≤P / (M*Q / A)≤0.

93.

4. The energy storage device of claim 1, wherein, The positive electrode material of the battery monomer includes lithium-containing phosphate, 2.8V≤U0≤3.6V, 250≤Y1*Y2≤468.

5. The energy storage device of claim 4, wherein, The positive electrode material of the battery monomer includes lithium-containing phosphate, 2.8V≤U0≤3.6V, 250≤Y1*Y2≤468.

6. The energy storage device of claim 4, wherein, 3.5*10 6 W≤P≤7.5*10 6 W, M = A, 1 ≤ X1*X2 ≤ 18.

7. The energy storage device of claim 6, wherein, X1＝1。 8. The energy storage device of claim 7, wherein, X2=1, 2000Ah≤C≤11000Ah.

9. The energy storage device of claim 8, wherein, 2500Ah≤C≤6000Ah.

10. The energy storage device of claim 7, wherein, X2=2, 1000Ah≤C≤5500Ah.

11. The energy storage device of claim 10, wherein, 2000Ah≤C≤4000Ah.

12. The energy storage device of claim 6, wherein, 2≤X1≤6。 13. The energy storage device of claim 12, wherein, X1=4, X2=1, 500Ah≤C≤2600Ah.

14. The energy storage device of claim 13, wherein, 800Ah≤C≤1500Ah.

15. The energy storage device of claim 12, wherein, X1=4, X2=2, 250Ah≤C≤1300Ah.

16. The energy storage device of claim 15, wherein, 350Ah≤C≤1000Ah.

17. The energy storage device of claim 16, wherein, 500Ah≤C≤700Ah.

18. The energy storage device of claim 12, wherein, X1 first battery groups are arranged along the length direction of the box body.

19. The energy storage device of claim 18, wherein, The battery compartment includes a plurality of sub-compartments, a plurality of sub-compartments are arranged along the length direction of the box body, and each sub-compartment contains one first battery group along the length direction of the box body.

20. The energy storage device of claim 1, wherein, The positive electrode material of the battery cell comprises a lithium transition metal oxide, 2.8V≤U0≤4.35V, 210≤Y1*Y2≤530.

21. The energy storage device of claim 20, wherein, 3.5*10 6 W≤P≤7.5*10 6 W, M = A, 1 ≤ X1*X2 ≤ 18.

22. The energy storage device of claim 21, wherein, X1＝1。 23. The energy storage device of claim 22, wherein, X2=1, 1500Ah≤C≤13400Ah.

24. The energy storage device of claim 23, wherein, 3000Ah≤C≤7000Ah.

25. The energy storage device of claim 22, wherein the electrolyte comprises a lithium salt. X2=2, 750Ah≤C≤6670Ah.

26. The energy storage device of claim 25, wherein, 1800Ah≤C≤4000Ah.

27. The energy storage device of claim 21, wherein, 2≤X1≤6。 28. The energy storage device of claim 27, wherein, X1=4, X2=1, 375Ah≤C≤3300Ah.

29. The energy storage device of claim 28, wherein, 700Ah≤C≤1600Ah.

30. The energy storage device of claim 27, wherein the electrolyte is a non-aqueous electrolyte. X1=4, X2=2, 200Ah≤C≤1600Ah.

31. The energy storage device of claim 30, wherein, 340Ah≤C≤1050Ah.

32. The energy storage device of claim 31, wherein the electrolyte is a non-aqueous electrolyte. 490Ah≤C≤720Ah.

33. The energy storage device of claim 27, wherein the electrolyte comprises a lithium salt. X1 first battery groups are arranged along the length direction of the box.

34. The energy storage device of claim 33, wherein the electrolyte is a non-aqueous electrolyte. The battery compartment comprises a plurality of sub-compartments, and the plurality of sub-compartments are arranged along the length direction of the box, and each of the sub-compartments contains one first battery group along the length direction of the box.

35. The energy storage device of claim 1, wherein, The battery cell is a sodium ion battery cell, 1.5V≤U0≤4V, 230≤Y1*Y2≤1000.

36. The energy storage device of claim 32, wherein the electrolyte comprises a lithium salt. 3.5*10 6 W≤P≤7.5*10 6 W, M = A, 1 ≤ X1*X2 ≤ 18.

37. The energy storage device of claim 36, wherein the electrolyte is a non-aqueous electrolyte. X1＝1。 38. The energy storage device of claim 37, wherein the electrolyte is a non-aqueous electrolyte. X2=1, 1200Ah≤C≤18000Ah.

39. The energy storage device of claim 38, wherein, 2000Ah≤C≤10000Ah.

40. The energy storage device of claim 37, wherein the electrolyte comprises a lithium salt. X2=2, 600Ah≤C≤9000Ah.

41. The energy storage device of claim 40, wherein the electrolyte is a non-aqueous electrolyte. 1600Ah≤C≤4000Ah.

42. The energy storage device of claim 36, wherein the electrolyte comprises a lithium salt. 2≤X1≤6。 43. The energy storage device of claim 42, wherein, X1=4, X2=1, 300Ah≤C≤4000Ah.

44. The energy storage device of claim 43, wherein the electrolyte is a non-aqueous electrolyte. 700Ah≤C≤1500Ah.

45. The energy storage device of claim 42, wherein the electrolyte comprises a lithium salt. X1=4, X2=2, 150Ah≤C≤1500Ah.

46. The energy storage device of claim 45, wherein the electrolyte is a non-aqueous electrolyte. 350Ah≤C≤1200Ah.

47. The energy storage device of claim 46, wherein the electrolyte is a non-aqueous electrolyte. 400Ah≤C≤650Ah.

48. The energy storage device of claim 42, wherein, X1 first battery groups are arranged along the length direction of the box.

49. The energy storage device of claim 48, wherein, The battery compartment comprises a plurality of sub-compartments, and the plurality of sub-compartments are arranged along the length direction of the box, and each of the sub-compartments contains one first battery group along the length direction of the box.

50. The energy storage device of any one of claims 1-49, wherein, Along the height direction of the box, the battery compartment contains only one first battery group, and Y1 battery cells in each first battery group are arranged along the height direction of the box, 2≤Y1≤10.

51. The energy storage device of any one of claims 1-49, wherein, The battery cell comprises a shell and at least one electrode assembly, and the electrode assembly is contained in the shell. The shell is in a straight parallelepiped shape, the size of the shell in the first direction is W1, the size of the shell in the second direction is T1, and the size of the shell in the third direction is K1, one of the first direction, the second direction and the third direction is parallel to the length direction of the box, another is parallel to the width direction of the box, and the remaining one is parallel to the height direction of the box. The shell comprises a first wall and a second wall arranged opposite along the first direction, a third wall and a fourth wall arranged opposite along the second direction, and a fifth wall and a sixth wall arranged opposite along the third direction, the sum of the thicknesses of the first wall and the second wall is a, the sum of the thicknesses of the third wall and the fourth wall is b, and the sum of the thicknesses of the fifth wall and the sixth wall is c, satisfying: (W1-a)*(T1-b)*(K1-c) / (W1*T1*K1)≥90%.

52. The energy storage device of claim 51, wherein, (W1-a) / W1≥97%, (T1-b) / T1≥96.5%, and (K1-c) / K1≥96.5%.

53. The energy storage device of claim 51, wherein the electrolyte comprises a lithium salt. The housing includes a shell and an end cap, the shell having an opening and the end cap closing the opening; The housing includes an integrally formed first wall, second wall, third wall, fourth wall and fifth wall, and the end cap is the sixth wall.

54. The energy storage device of claim 53, wherein, The battery cell further includes a first insulating member and a second insulating member. The first insulating member is disposed between the fifth wall and the electrode assembly and abuts against the fifth wall. The second insulating member is disposed between the sixth wall and the electrode assembly and abuts against the sixth wall. The maximum dimension of the first insulating member in the third direction is e1, and the maximum dimension of the second insulating member in the third direction is e2, satisfying: (W1-a-1.6mm)*(T1-b-1.6mm)*(K1-c-e1-e2) / (W1*T1*K1)≥88%, 0.3mm≤e1≤1.2mm, and 2mm≤e2≤10mm.

55. The energy storage device of claim 53, wherein the electrolyte comprises a lithium salt. The battery cell further includes a first insulating member and a second insulating member. The first insulating member is disposed between the fifth wall and the electrode assembly and abuts against the fifth wall. The second insulating member is disposed between the sixth wall and the electrode assembly and abuts against the sixth wall. The maximum dimension of the first insulating member in the third direction is e1, and the maximum dimension of the second insulating member in the third direction is e2, satisfying: (W1-a-4mm)*(T1-b-4mm)*(K1-c-e1-e2) / (W1*T1*K1)≥85%, 0.3mm≤e1≤1.2mm, and 2mm≤e2≤10mm.

56. The energy storage device of claim 53, wherein the electrolyte comprises a lithium salt. W1≥T1, the first direction is parallel to the length direction of the box, the second direction is parallel to the width direction of the box, and the third direction is parallel to the height direction of the box.

57. The energy storage device of claim 51, wherein the electrolyte comprises a lithium salt. The housing includes a shell and two end caps. The shell has two openings disposed opposite to each other along the third direction, and the two end caps respectively cover the two openings. The housing includes an integrally formed first wall, second wall, third wall and fourth wall, and the two end caps are the fifth wall and the sixth wall, respectively.

58. The energy storage device of claim 57, wherein, The battery cell further includes a third insulating member and a fourth insulating member. The third insulating member is disposed between the fifth wall and the electrode assembly and abuts against the fifth wall. The fourth insulating member is disposed between the sixth wall and the electrode assembly and abuts against the sixth wall. The maximum dimension of the third insulating member in the third direction is e3, and the maximum dimension of the fourth insulating member in the third direction is e4, satisfying: (W1-a-1.6mm)*(T1-b-1.6mm)*(K1-c-e3-e4) / (W1*T1*K1)≥88%, 2mm≤e3≤10mm, and 2mm≤e4≤10mm.

59. The energy storage device of claim 57, wherein the electrolyte comprises a lithium salt. The battery monomer further comprises a third insulation piece and a fourth insulation piece, the third insulation piece is arranged between the fifth wall and the electrode assembly and abuts against the fifth wall, and the fourth insulation piece is arranged between the sixth wall and the electrode assembly and abuts against the sixth wall. The maximum dimension of the third insulation piece in the third direction is e3, the maximum dimension of the fourth insulation piece in the third direction is e4, and the following conditions are met: (W1-a-4mm)*(T1-b-4mm)*(K1-c-e3-e4) / (W1*T1*K1)≥85%, 2mm≤e3≤10mm, and 2mm≤e4≤10mm.

60. The energy storage device of claim 57, wherein, W1≥T1, the first direction is parallel to the height direction of the box body, the second direction is parallel to the width direction of the box body, and the third direction is parallel to the length direction of the box body.

61. The energy storage device of claim 51, wherein, 3000 cm 3 ≤ W1*T1*K1 ≤ 40000 cm 3 .

62. The energy storage device of claim 61, wherein, 3200cm 3 ≤ W1*T1*K1 ≤ 32000 cm 3 .

63. The energy storage device of claim 62, wherein, 3720 cm 3 ≤ W1 * T1 * K1 ≤ 12500 cm 3 .

64. The energy storage device of claim 63, wherein, 4000 cm 3 ≤ W1 * T1 * K1 ≤ 6000 cm 3 .

65. The energy storage device of claim 51, wherein, The positive electrode material of the battery monomer comprises lithium-containing phosphate, and the following conditions are met: C≥350Ah, and C / ((W1-a)*(T1-b)*(K1-c))≥118Ah / L.

66. The energy storage device of claim 51, wherein, The positive electrode material of the battery monomer comprises lithium transition metal oxide, and the following conditions are met: C≥650Ah, and C / ((W1-a)*(T1-b)*(K1-c))≥190Ah / L.

67. The energy storage device of claim 51, wherein the carbon nanotube is a single- walled carbon nanotube. The battery monomer is a sodium ion battery monomer, and the following conditions are met: C≥260Ah, and C / ((W1-a)*(T1-b)*(K1-c))≥87Ah / L.

68. An energy storage system, comprising: Comprise: An energy storage converter; M energy storage devices as claimed in any one of claims 1-67, the energy storage devices being electrically connected to the energy storage converter.

69. The energy storage system of claim 68, wherein, M=2, A=2; or, M=4, A=4; or, M=8, A=8.

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