Negative electrode current collector, negative electrode structure and molten lithium metal battery structure
By using a negative electrode current collector with a stopper and an elastic part in a molten lithium metal battery, the problem of unstable contact in the battery under high temperature is solved, and the effect of fast charging and discharging and avoiding the dead lithium area is achieved.
Patent Information
- Application Number
- CN202421966824.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-14
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2034-08-14
AI Technical Summary
The existing molten lithium metal batteries are difficult to maintain stable contact between the negative electrode current collector and the molten lithium under high temperature conditions, and a dead lithium zone is easily formed during the charging and discharging process, which hinders the full charging and discharging of the battery.
A negative electrode current collector is adopted, which includes a stopper and an elastic part, which is used to contact with molten lithium, and the elastic part provides elastic deformation to maintain a contact force by connecting to the pole and the stopper.
By increasing the contact area between molten lithium and solid electrolyte and negative electrode current collector, fast charging and discharge are achieved, and the formation of dead lithium zones are avoided, ensuring the stable and efficient performance of the battery.
Smart Images
Figure CN222939937U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, in particular to a negative electrode current collector, a negative electrode structure and a molten lithium metal battery structure. Background Art
[0002] At present, as a representative of new energy energy storage systems, lithium-ion batteries have been widely used in all aspects of society due to their excellent electrochemical performance. However, traditional lithium-ion batteries mostly use liquid organic electrolytes and often face the risk of electrolyte leakage, combustion and explosion.
[0003] Solid electrolytes are considered to be ideal substitutes for organic electrolytes due to their wide electrochemical window, excellent thermal stability and chemical stability. Based on the above advantages of solid electrolytes, molten lithium metal batteries with solid electrolytes as the target electrolytes have the characteristics of high safety, high energy density and low cost, and are considered to be strong candidates for the next-generation large-scale power grid energy storage. However, due to its surface tension, molten metallic lithium will be in a droplet state, and this state has a poor contact effect with the external structure. Moreover, molten metallic lithium has poor fluidity and will remain on the negative electrode current collector, forming dead lithium. Due to the characteristics of molten metallic lithium, existing molten lithium metal batteries have the technical problems that it is difficult for the negative electrode current collector to maintain stable and lasting good contact with molten lithium at high temperatures, and dead lithium is formed during the charge and discharge process of the battery, making it impossible to achieve full charge and discharge, which hinders its further development. Summary of the Utility Model
[0004] The first object of the utility model is to provide a negative electrode current collector which can maintain stable and lasting good contact with molten lithium and is not prone to dead lithium areas during the charge and discharge process of the battery, so as to achieve full charge and discharge.
[0005] The second object of the utility model is to provide a negative electrode structure which can enable the negative electrode current collector to maintain stable and lasting good contact with molten lithium and is not prone to dead lithium areas during the charge and discharge process of the battery, so as to achieve full charge and discharge.
[0006] The third object of the utility model is to provide a molten lithium metal battery which can enable the negative electrode current collector to maintain stable and lasting good contact with molten lithium and is not prone to dead lithium areas during the charge and discharge process of the battery, so as to achieve full charge and discharge.
[0007] To achieve the above object, the utility model adopts the following technical solutions:
[0008] The present utility model discloses a negative electrode current collector, comprising: a pole column part; a stopping part which is arranged at an interval from the pole column part and is used for contacting molten lithium; and an elastic part, one end of the elastic part is connected or abutted to the pole column part, and the other end is connected to the stopping part.
[0009] In some embodiments, the elastic part comprises at least one of a helical spring, a disc spring, and a corrugated spring.
[0010] In some embodiments, one end of the elastic part is connected to the stopping part by welding.
[0011] In some embodiments, one end of the elastic part is connected to the stopping part by snap connection; wherein, a snap projection is provided on one of the elastic part and the stopping part, and a snap groove cooperating with the snap projection is provided on the other of the elastic part and the stopping part.
[0012] In some embodiments, one end of the elastic part is connected to the stopping part by a connecting member, wherein: the connecting member comprises any one of a screw, a rivet, or a pin.
[0013] In some embodiments, the stopping part is any one of a stainless steel part, a metal chromium part, a metal nickel part, or an iron-nickel alloy part; and / or: the elastic part is a conductive part, and the elastic part is a stainless steel part or a titanium alloy part.
[0014] The present utility model also discloses a negative electrode structure, comprising a lining part, a solid electrolyte, and the above-mentioned negative electrode current collector, wherein, one end of the lining part is open, the solid electrolyte is installed at the open end of the lining part and encloses a negative electrode chamber, and the negative electrode current collector is installed in the negative electrode chamber.
[0015] In some embodiments, the cross-sectional area of the stopping part is smaller than the cross-sectional area of the negative electrode chamber.
[0016] In some embodiments, the distance between the outer side wall of the stopping part and the inner side wall of the negative electrode chamber is less than 0.2 mm.
[0017] The present utility model also discloses a molten lithium metal battery structure, comprising a metal shell, a solid electrolyte, a lining part, and the negative electrode current collector described above, wherein, the metal shell is hermetically connected to the solid electrolyte and the lining part, and the solid electrolyte divides the metal shell into a positive electrode chamber and a negative electrode chamber.
[0018] Beneficial effects of the negative electrode current collector of the present utility model: Since the negative electrode current collector of this embodiment includes a stopping portion in contact with molten lithium and an elastic portion, when the battery is in the initial charging state, the stopping portion of the negative electrode current collector fits against the top surface of the solid electrolyte, and the deformation amount of the elastic portion of the negative electrode current collector is zero; during the charging process, molten lithium is continuously generated in the negative electrode chamber. The generated molten lithium will push against the stopping portion. As the generated molten lithium continuously increases, the force exerted by the molten lithium against the stopping portion becomes greater. At the same time, the reaction force of the stopping portion against the molten lithium will also become greater, causing the molten lithium that tends to form a droplet shape to be pressed into a flat shape, effectively increasing the contact area between the molten lithium and the solid electrolyte and the negative electrode current collector, thereby facilitating rapid charging, especially for the rapid charging of an anode-free battery. When enough molten lithium is generated, the force generated will cause the elastic portion of the negative electrode current collector to be compressed and deformed. By the end of the charging process, the deformation amount of the elastic portion is the largest; during the discharging process, the molten lithium in the negative electrode chamber will continuously lose electrons to form Li + , Li + moves towards the positive electrode, and the amount of molten lithium continuously decreases. At this time, due to the elastic action of the elastic portion, the negative electrode current collector will gradually recover its deformation and continue to maintain the pressure on the molten lithium, ensuring the contact between the molten lithium and the solid electrolyte and the negative electrode current collector during discharging, which is beneficial for completing rapid discharging.
[0019] Beneficial effects of the negative electrode structure of the present utility model: Due to having the negative electrode current collector described above, this negative electrode structure can enable the negative electrode current collector to maintain stable and lasting good contact with molten lithium, and it is not easy to form a dead lithium area during the charge and discharge process of the battery, achieving full charge and discharge.
[0020] Beneficial effects of the molten lithium metal battery structure of the present utility model: Due to having the negative electrode current collector described above, this molten lithium metal battery can enable the negative electrode current collector to maintain stable and lasting good contact with molten lithium, and it is not easy to form a dead lithium area during the charge and discharge process of the battery, achieving full charge and discharge.
[0021] Additional aspects and advantages of the present utility model will be given in part in the following description, will become apparent in part from the following description, or will be understood through the practice of the present utility model. Description of the Drawings
[0022] Figure 1 are schematic structural diagrams of the negative electrode structure of the prior art before charging, during charging, at the end of charging, and at the end of discharging;
[0023] Figure 2 is a schematic structural diagram of the negative electrode current collector of the embodiment of the present utility model;
[0024] Figure 3 is a schematic structural diagram of the negative electrode structure of the embodiment of the present utility model;
[0025] Figure 4 are schematic diagrams of the negative electrode structure of the embodiment of the present utility model before charging, during charging, after charging, and after discharging;
[0026] Figure 5 is a schematic diagram of the structure of the molten lithium metal battery structure of the embodiment of the present utility model.
[0027] Reference numerals:
[0028] Figure 1 in:
[0029] 1. Negative current collector; 11. Bottom sheet; 2. Solid electrolyte; 3. Negative electrode chamber; 4. Dead lithium area;
[0030] Figures 2 - 5 in:
[0031] 100. Terminal part; 200. Abutted part; 300. Elastic part; 400. Solid electrolyte; 500. Metal shell; 600. Negative electrode chamber; 700. Lining part; 800. Positive electrode chamber. Detailed implementation manners
[0032] The present utility model will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. Additionally, it should be noted that for the convenience of description, only parts related to the present utility model rather than all structures are shown in the drawings. In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.
[0033] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "above and over", and "on the top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "below", "below and under", and "under the bottom of" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.
[0034] In the description of this embodiment, the terms "upper", "lower", "right", and other orientation or position relationships are based on the orientation or position relationships shown in the drawings. They are only for the convenience of description and simplifying operations, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.
[0035] Referring to Figure 1 As shown, during the charge and discharge process of the existing negative electrode current collector 1, when the battery is in the initial charging state, the bottom sheet 11 of the negative electrode current collector 1 is in contact with the top surface of the solid electrolyte 2. During the charging process, molten lithium is continuously generated in the negative electrode chamber 3. As the generated molten lithium continuously increases, the contact area between the molten lithium and the negative electrode current collector 1 will gradually increase until the charging is completed; during the discharging process, the molten lithium will continuously lose electrons to form Li + Li + will move towards the positive electrode, and the molten lithium in the negative electrode chamber 3 will continuously decrease. However, due to the poor fluidity of the molten lithium, a dead lithium area 4 will be formed above the negative electrode current collector 1, and it cannot be fully discharged, resulting in a decrease in the Coulomb efficiency of the battery.
[0036] In the present utility model, referring to Figure 2 As shown, the negative electrode current collector disclosed in the present utility model is used for a molten lithium metal battery and includes a pole column part 100, a stop part 200, and an elastic part 300. The stop part 200 is arranged at an interval from the pole column part 100, and the stop part 200 is used for contacting the molten lithium. One end of the elastic part 300 is connected to or abuts against the pole column part 100, and the other end is connected to the stop part 200. It can be understood that since the negative electrode current collector of this embodiment includes the stop part 200 and the elastic part 300 that contact the molten lithium, referring to Figure 3 and Figure 4 As shown, when the battery is in the initial charging state, the stop part 200 of the negative electrode current collector is in contact with the top surface of the solid electrolyte 400, and the deformation amount of the elastic part 300 of the negative electrode current collector is zero; during the charging process, molten lithium is continuously generated in the negative electrode chamber 600, and the generated molten lithium will push against the stop part 200. As the generated molten lithium continuously increases, the greater the force of the molten lithium pushing against the stop part 200, and at the same time, the greater the reaction force of the stop part 200 on the molten lithium, so that the molten lithium that tends to form a droplet shape is pressed into a flat shape, effectively increasing the contact area between the molten lithium and the solid electrolyte 400, which is beneficial to completing rapid charging, especially beneficial to the rapid charging of an anode-free battery. When the generated molten lithium is sufficient, the force generated will cause the elastic part 300 of the negative electrode current collector to be compressed and deformed until the deformation amount of the elastic part 300 is the largest when the charging is completed; during the discharging process, the molten lithium in the negative electrode chamber 600 will continuously lose electrons to form Li +, Li + moves towards the positive electrode, and the amount of molten lithium continuously decreases. At this time, due to the elastic action of the elastic part 300, the negative electrode current collector will gradually recover its deformation and continue to maintain the pressure on the molten lithium, ensuring the contact between the molten lithium, the solid electrolyte 400, and the negative electrode current collector during discharge, which is beneficial to complete rapid discharge. In addition, due to the structural design of the negative electrode current collector in this embodiment, compared with the traditional current collector, it can avoid the generated molten lithium running above the negative electrode current collector, and because of its poor fluidity, it cannot be discharged, resulting in the phenomenon of dead lithium remaining above the negative electrode current collector.
[0037] Optionally, the elastic part 300 includes at least one of a helical spring, a disc spring, and a corrugated spring. It should be noted that in the embodiment of the present utility model, the elastic part 300 can select any one of a helical spring, a disc spring, and a corrugated spring according to actual needs, or it can be a combined structure of a helical spring and a disc spring, or it can also be a combined structure of a disc spring and a corrugated spring, or it can also be a combined structure of a helical spring, a disc spring, and a corrugated spring. The elastic coefficient of the elastic part 300 can be selected according to actual needs, and the elastic coefficient of the elastic part 300 is not specifically limited herein.
[0038] Optionally, one end of the elastic part 300 is welded to the abutting part 200. It can be understood that welding the elastic part 300 to the abutting part 200 can facilitate the manufacture of the negative electrode current collector and ensure the connection stability between the elastic part 300 and the abutting part 200.
[0039] Optionally, one end of the elastic part 300 is snap-connected to the abutting part 200; wherein, a snap projection is provided on one of the elastic part 300 and the abutting part 200, and a snap groove cooperating with the snap projection is provided on the other of the elastic part 300 and the abutting part 200. It can be understood that in some embodiments, the elastic part 300 is provided with a snap projection and the abutting part 200 is provided with a snap groove; in some embodiments, the elastic part 300 is provided with a snap groove and the abutting part 200 is provided with a snap projection. The connection between the elastic part 300 and the abutting part 200 is realized through the snap groove and the snap projection, and the connection is very convenient and can realize detachable connection. The negative electrode current collector can be repaired according to actual needs during actual work. It should be added here that in the embodiment of the present utility model, the number, shape, and arrangement mode of the snap projection and the snap groove can all be selected according to actual needs, and the relevant parameters of the snap groove and the snap groove are not limited herein.
[0040] Optionally, one end of the elastic part 300 is connected to the abutting part 200 through a connecting member, where: the connecting member includes any one of a screw, a rivet, or a pin. The connection between the elastic part 300 and the abutting part 200 is realized through the connecting member, and the connection is very convenient and can realize detachable connection. The negative electrode current collector can be repaired according to actual needs during actual work.
[0041] Optionally, the abutting portion 200 is made of a material that is conductive and stable to lithium chemistry. For example, the abutting portion 200 is any one of a stainless steel part, a chromium metal part, a nickel metal part, or an iron-nickel alloy part. It can be understood that the abutting portion 200 being a conductive material part can ensure the electrical conductivity of the negative electrode current collector, and the abutting portion 200 being a material that is stable to lithium chemistry can avoid the reaction between the abutting portion 200 and molten lithium, ensuring the stability of the negative electrode current collector. Of course, in other embodiments of the present invention, the elastic portion 300 can also be selected as other conductive material parts that are heat-resistant and do not react with molten lithium according to needs.
[0042] Optionally, the elastic portion 300 is a conductive part, and the elastic portion 300 is a stainless steel part or a titanium alloy part. It can be understood that the abutting portion 200 being a conductive material part can ensure the electrical conductivity of the negative electrode current collector. Of course, in other embodiments of the present invention, the elastic portion 300 can also be selected as other heat-resistant conductive material parts according to needs.
[0043] The present invention also discloses a negative electrode structure for a molten lithium metal battery, which includes a lining member 700, a solid electrolyte 400, and the aforementioned negative electrode current collector. One end of the lining member 700 is open, the solid electrolyte 400 is installed at the open end of the lining member 700 and encloses a negative electrode chamber 600, and the negative electrode current collector is installed in the negative electrode chamber 600. Due to the aforementioned negative electrode current collector, during the charging process, the contact area between the molten lithium and the solid electrolyte 400 and the negative electrode current collector can be effectively increased, which is beneficial to completing rapid charging. During the discharging process, the contact between the molten lithium and the solid electrolyte 400 and the negative electrode current collector can be ensured, which is beneficial to completing rapid discharging and avoiding the generation of a dead lithium area.
[0044] Optionally, the cross-sectional area of the abutting portion 200 is smaller than the cross-sectional area of the negative electrode chamber 600. According to the foregoing, during the actual working process, the abutting portion 200 will move within the negative electrode chamber 600. The cross-sectional area of the abutting portion 200 being smaller than the cross-sectional area of the negative electrode chamber 600 can avoid friction between the abutting portion 200 and the negative electrode chamber 600, ensuring that the abutting portion 200 can move stably.
[0045] Optionally, the distance between the outer wall of the abutting portion 200 and the inner wall of the negative electrode chamber 600 is less than 0.2 mm. If the distance between the outer wall of the abutting portion 200 and the inner wall of the negative electrode chamber 600 is too large, molten lithium may enter the upper part of the abutting portion 200 through the gap between the outer wall of the abutting portion 200 and the inner wall of the negative electrode chamber 600. Controlling the distance between the outer wall of the abutting portion 200 and the inner wall of the negative electrode chamber 600 within a range less than 0.2 mm can reduce the probability of molten lithium entering the upper part of the abutting portion 200 through the gap between the outer wall of the abutting portion 200 and the inner wall of the negative electrode chamber 600 while ensuring the stable movement of the abutting portion 200, thereby further reducing the probability of the occurrence of the dead lithium area.
[0046] The present utility model also discloses a molten lithium metal battery structure. Refer to Figure 5 As shown, the molten lithium metal battery structure includes a metal shell 500, a solid electrolyte 400, a lining member 700, and the negative electrode current collector described above. Among them, the metal shell 500 is hermetically connected to the solid electrolyte 400 and the lining member 700 (the hermetic connection method can be carried out by any one of glass and inorganic salts). The solid electrolyte 400 divides the metal shell 500 into a positive electrode chamber 800 and a negative electrode chamber 600. Due to the negative electrode current collector described above, during the charging process, the contact area between the molten lithium and the solid electrolyte 400 and the negative electrode current collector can be effectively increased, which is beneficial to complete rapid charging. During the discharging process, the contact between the molten lithium and the solid electrolyte 400 and the negative electrode current collector can be ensured, which is beneficial to complete rapid discharging and avoid the generation of the dead lithium area.
[0047] In the description of this specification, the descriptions referring to terms such as "some embodiments", "other embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.
[0048] Obviously, the above embodiments of the present utility model are merely examples for clearly illustrating the present utility model and are not intended to limit the implementation manners of the present utility model. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present utility model. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present utility model shall be included in the protection scope of the claims of the present utility model.
Claims
1. A negative electrode current collector for a molten lithium metal battery, characterized in that: include: A pole portion (100); A stop portion (200), the stop portion (200) being spaced apart from the pole portion (100), and the stop portion (200) being used to contact with molten lithium; An elastic part (300), one end of the elastic part (300) is connected to or abuts the pole part (100), and the other end is connected to the stop part (200).
2. The negative electrode current collector according to claim 1, characterized in that: The elastic part (300) comprises at least one of a coil spring, a butterfly spring and a wave spring.
3. The negative electrode current collector according to claim 1, characterized in that: One end of the elastic portion (300) is welded to the stop portion (200).
4. The negative electrode current collector according to claim 1, characterized in that: One end of the elastic part (300) is connected to the stop part (200) by snapping; wherein, one of the elastic part (300) and the stop part (200) is provided with a snapping protrusion, and the other of the elastic part (300) and the stop part (200) is provided with a snapping groove that cooperates with the snapping protrusion.
5. The negative electrode current collector according to claim 1, characterized in that: One end of the elastic portion (300) is connected to the stop portion (200) via a connecting piece, wherein the connecting piece comprises any one of a screw, a rivet or a pin.
6. The negative electrode current collector according to claim 1, characterized in that: The stop portion (200) is any one of a stainless steel part, a metal chromium part, a metal nickel part or an iron-nickel alloy part; and / or: The elastic part (300) is a conductive part, and the elastic part (300) is a stainless steel part or a titanium alloy part.
7. A negative electrode structure, characterized in that: It comprises an inner lining member (700), a solid electrolyte (400) and a negative electrode current collector as described in any one of claims 1 to 6, wherein one end of the inner lining member (700) is open, the solid electrolyte (400) is installed on the open end of the inner lining member (700) and encloses a negative electrode chamber (600), and the negative electrode current collector is installed in the negative electrode chamber (600).
8. The negative electrode structure according to claim 7, characterized in that: The cross-sectional area of the stop portion (200) is smaller than the cross-sectional area of the negative electrode chamber (600).
9. The negative electrode structure according to claim 8, characterized in that: The distance between the outer wall of the stop portion (200) and the inner wall of the negative electrode chamber (600) is less than 0.2 mm.
10. A molten lithium metal battery structure, characterized in that: It comprises a metal shell (500), a solid electrolyte (400), an inner lining (700) and a negative electrode current collector as described in any one of claims 1 to 6, wherein the metal shell (500) is packaged and connected with the solid electrolyte (400) and the inner lining (700), and the solid electrolyte (400) divides the metal shell (500) into a positive electrode chamber and (800) a negative electrode chamber (600).