Battery

Abstract

The invention provides a battery. The battery comprises an outer shell, a thermosensitive inner shell, an additive interlayer, a control module and a heating module, the thermosensitive inner shell is arranged on the inner side of the outer shell; the additive interlayer is arranged between the outer shell and the thermosensitive inner shell; the control module is used for detecting a battery health state value of the battery cell and comparing the battery health state value of the battery cell with a preset threshold value, and when the battery health state value of the battery cell is smaller than the preset threshold value, the control module drives the heating module to work; the heating module is arranged at the thermosensitive inner shell, the heating module responds to the working instruction of the control module, and the heating module heats the thermosensitive inner shell to the shrinkage temperature for preset time. When the control module detects that the battery health state value of the battery cell is lower than a preset threshold value, the heating module heats the thermosensitive inner shell, the thermosensitive inner shell shrinks, the additive interlayer makes contact with the electrolyte, and the additive in the additive interlayer is dissolved into the electrolyte, so that the battery health state value of the battery cell is increased, the battery performance is improved, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of battery equipment, and in particular to a battery. Background Art

[0002] In recent years, lithium-ion batteries have been widely used in many emerging fields, especially in energy storage power stations, due to their high energy density and easy-to-use design. Lithium-ion batteries are composed of anodes, cathodes, electrolytes and separators. The main function of the electrolyte is to transfer lithium ions and anions between the positive and negative electrodes as an ion carrier. Although the basic properties of lithium-ion batteries, such as the operating voltage and energy density, are mainly determined by the composition materials of the positive and negative electrodes, the design optimization of the electrolyte is also crucial to obtain long life and stable cycle performance. In particular, the electrolyte additive regulation strategy has always been regarded as "the simplest way to improve battery performance."

[0003] In production practice, vinyl carbonate (VC) has become the most widely used electrolyte film-forming additive in long-life energy storage cells (especially lithium iron phosphate / graphite system) due to its good film-forming properties. The content of vinyl carbonate (VC) in the battery will gradually decrease as the battery is used. The content of vinyl carbonate (VC) in the battery is related to the SOH value (battery health status value) of the battery. Too low a content of vinyl carbonate (VC) may cause the battery to be consumed too quickly during long-term cycles and fail to maintain a stable SEI film (solid electrolyte interface film), resulting in a sudden drop in the battery capacity and a reduction in the battery's SOH value (battery health status value). Although a high content of vinyl carbonate (VC) helps to form a stable SEI film (solid electrolyte interface film), if an excessive amount of vinyl carbonate (VC) is added when making the battery, it may increase the impedance of the film formation, causing lithium precipitation, and also reduce the battery's SOH value (battery health status value), or even battery failure.

[0004] In existing battery designs, the electrolyte and its additives are usually filled once and are not replenished during the entire life cycle of the battery, which limits the further improvement of battery performance and the extension of battery life. Summary of the invention

[0005] Based on this, it is necessary to provide a battery to address the above technical problems.

[0006] A battery, comprising: an outer shell, a thermosensitive inner shell, an additive interlayer, a control module and a heating module;

[0007] The heat-sensitive inner shell is arranged on the inner side of the outer shell;

[0008] The additive interlayer is disposed between the outer shell and the heat-sensitive inner shell;

[0009] The control module is used to detect the battery health state value of the battery cell, and compare the battery health state value of the battery cell with a preset threshold. When the battery health state value of the battery cell is less than the preset threshold, the control module drives the heating module to operate;

[0010] The heating module is arranged at the thermosensitive inner shell. The heating module responds to the working instruction of the control module, and the heating module heats the thermosensitive inner shell to the shrinkage temperature at which the thermosensitive inner shell shrinks, and lasts for a preset time.

[0011] In one embodiment, the mass ratio of the additive interlayer to the mass of the electrolyte in the battery cell is 0.5-9%.

[0012] In one embodiment, the shrinkage temperature of the thermosensitive inner shell is lower than the deformation temperature of the outer shell.

[0013] In one embodiment, the shrinkage temperature of the thermosensitive inner shell is lower than the decomposition temperature of the electrolyte.

[0014] In one embodiment, when the temperature of the thermosensitive inner shell is lower than the shrinkage temperature, the thermosensitive inner shell maintains its original shape.

[0015] In one embodiment, the material of the thermosensitive inner shell is an electrochemically inert material.

[0016] In one embodiment, the thermosensitive inner shell is at least one of polyethylene, polypropylene, polyvinylidene fluoride and heat-shrinkable rubber materials.

[0017] In one embodiment, the control module is a battery management system.

[0018] In one embodiment, it further includes a top cover. The shapes of the outer shell and the thermosensitive inner shell are both rectangular parallelepiped, and openings are provided at the same end of the outer shell and the thermosensitive inner shell, and the top cover is arranged at the opening of the outer shell.

[0019] In one embodiment, the material of the outer shell includes at least one of aluminum, aluminum alloy, copper alloy, and stainless steel.

[0020] The above-mentioned battery is provided with an additive interlayer between the outer shell and the thermosensitive inner shell in the battery. The control module detects the state-of-health value of the battery cell. When the state-of-health value of the battery cell is lower than the preset threshold, it is determined that the health value of the battery cell has decreased. The control module drives the heating module to heat the thermosensitive inner shell, causing the thermosensitive inner shell to shrink, so that the additive interlayer contacts the electrolyte, and the additives in the additive interlayer dissolve into the electrolyte, improving the state-of-health value of the battery. Without disassembling the battery or adding extra electrolyte, the battery performance can be improved and the service life of the battery can be extended. Description of the Drawings

[0021] Figure 1 It is a schematic diagram of the structure of a single battery cell in an embodiment.

[0022] 100. Outer shell; 110. Battery cell; 120. Top cover; 130. Positive electrode tab; 140. Negative electrode tab; 200. Thermosensitive inner shell; 300. Additive interlayer. Detailed Embodiments

[0023] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0024] Embodiment 1

[0025] As Figure 1 shown, a battery includes: an outer shell 100, a thermosensitive inner shell 200, an additive interlayer 300, a control module and a heating module;

[0026] The thermosensitive inner shell 200 is arranged inside the outer shell 100;

[0027] The additive interlayer 300 is arranged between the outer shell 100 and the thermosensitive inner shell 200;

[0028] The control module is used to detect the state-of-health value of the battery cell 110, and compare the state-of-health value of the battery cell 110 with the preset threshold. When the state-of-health value of the battery cell 110 is less than the preset threshold, the control module drives the heating module to work;

[0029] The heating module is arranged at the thermosensitive inner shell 200. The heating module responds to the working instruction of the control module. The heating module heats the thermosensitive inner shell 200 to the shrinkage temperature at which the thermosensitive inner shell 200 shrinks, and lasts for a preset time.

[0030] In this embodiment, the heating module is the battery cell 110, and the battery cell 110 is disposed inside the thermal inner shell 200. An additive interlayer 300 is provided between the battery outer shell 100 and the thermal inner shell 200. When the control module detects that the battery health state value of the battery cell 110 is lower than a preset threshold, it drives the heating module to operate, heats the thermal inner shell 200 to the shrinkage temperature, causes the thermal inner shell 200 to shrink, and thus releases the electrolyte additive in the additive interlayer 300. In-situ replenishment of the electrolyte additive is achieved, without the need to disassemble the battery or add electrolyte additionally, simplifying the maintenance process and reducing the maintenance cost. By timely replenishing the electrolyte additive when the battery health state deteriorates, the attenuation rate of the battery performance can be effectively slowed down, the service life of the battery can be extended, and the economy and reliability of the battery can be improved.

[0031] In one embodiment, the mass ratio of the additive interlayer 300 to the mass of the electrolyte in the battery cell 110 is 0.5 - 9%.

[0032] In the above embodiment, to ensure the suitability of the additive replenishment amount and set a reasonable mass ratio range can ensure that when the battery health state deteriorates, the dosage of the electrolyte additive released by the additive interlayer 300 can not only meet the requirements for battery performance recovery and improvement, but also will not cause problems such as an increase in side reactions inside the battery and an increase in impedance due to excessive addition.

[0033] In addition, different battery types (such as lithium iron phosphate batteries, ternary lithium batteries, etc.) and application scenarios (such as electric vehicles, energy storage systems, etc.) may have different requirements for electrolyte additives. By setting the mass ratio range, the specific requirements of different batteries and application scenarios can be adapted.

[0034] In one embodiment, the shrinkage temperature of the thermal inner shell 200 is lower than the deformation temperature of the outer shell 100.

[0035] In the above embodiment, the deformation temperature of the outer shell 100 refers to the critical temperature at which its structure deforms at high temperature. The shrinkage temperature of the thermal inner shell 200 is lower than the deformation temperature of the outer shell 100. During the process of thermal shrinkage deformation of the thermal inner shell 200 to release the additive, the outer shell 100 will not be affected by high temperature and deform. This can effectively maintain the structural integrity and tightness of the outer shell 100, prevent problems such as the exposure of the internal environment of the battery or electrolyte leakage caused by the deformation of the outer shell 100, and ensure the normal operation and safety of the battery. When the control module heats the thermal inner shell 200, it can more precisely control the heating temperature to avoid overheating and causing the outer shell 100 to deform. This precise temperature control helps to achieve the accurate release of the additive, ensure that the effect and timing of additive replenishment meet the requirements of battery performance maintenance, and avoid problems such as incomplete or uneven release of the additive caused by too high or too low temperature.

[0036] In one embodiment, the shrinkage temperature of the thermosensitive inner shell 200 is lower than the decomposition temperature of the electrolyte.

[0037] In the above embodiment, the decomposition temperature of the electrolyte is the critical temperature at which the electrolyte undergoes chemical decomposition at high temperatures. During the decomposition process, heat, gas, etc. may be generated, resulting in an increase in the internal temperature and pressure of the battery, and even triggering safety accidents such as thermal runaway. The shrinkage temperature of the thermosensitive inner shell 200 being lower than the decomposition temperature of the electrolyte means that when the thermosensitive inner shell 200 undergoes thermal shrinkage deformation to release the additive, the internal temperature of the battery has not reached the dangerous level of electrolyte decomposition.

[0038] The shrinkage temperature of the thermosensitive inner shell 200 being lower than the decomposition temperature of the electrolyte provides precise temperature control conditions for the release of the additive. When the battery health state value is lower than the preset threshold, the control module drives the heating module to heat the thermosensitive inner shell 200 to its shrinkage temperature. At this time, the thermosensitive inner shell 200 undergoes thermal shrinkage deformation and releases the additive. Since the shrinkage temperature is lower than the electrolyte decomposition temperature, the heating process will not damage the electrolyte, ensuring the accuracy and effectiveness of the additive release, achieving precise control of the additive release, and avoiding problems such as additive failure or electrolyte performance degradation caused by excessive temperature.

[0039] In one embodiment, when the temperature of the thermosensitive inner shell 200 is lower than the shrinkage temperature, the thermosensitive inner shell 200 maintains its original shape.

[0040] In the above embodiment, under the normal operating state of the battery, the temperature of the thermosensitive inner shell 200 is usually lower than its shrinkage temperature. At this time, the thermosensitive inner shell 200 maintains its original shape and can tightly wrap the additive sandwich 300. This sealing property ensures that the additive will not leak from the sandwich when it does not need to be released, avoiding waste of the additive and possible interference with the internal environment of the battery.

[0041] The stable shape of the thermosensitive inner shell 200 can provide stable support and positioning for the battery core 110, electrolyte, etc. inside the battery, so that the structure of the battery will not deform or shift under various usage conditions.

[0042] The thermosensitive inner shell 200 will not undergo thermal shrinkage deformation when the temperature is lower than the shrinkage temperature, which means that within the normal operating temperature range of the battery, the thermosensitive inner shell 200 will not have unnecessary thermal responses due to temperature fluctuations.

[0043] In one embodiment, the material of the thermosensitive inner shell 200 is an electrochemically inert material.

[0044] In the above embodiments, the electrolyte usually contains chemical substances such as lithium salts and organic solvents and has certain activity. Electrochemically inert substances will not react with the chemical components in the electrolyte in the electrochemical environment of the battery. Let the material of the thermosensitive inner shell 200 be an electrochemically inert material, which will not react with the chemical components in the electrolyte in the electrochemical environment of the battery, maintaining the stability of the electrolyte and the electrochemical performance of the battery. During the cycling of the battery, the interface between the electrode and the electrolyte will change, and the electrochemically inert material will not participate in these interfacial reactions, thus avoiding the impact on the cycling stability of the battery.

[0045] In one embodiment, the thermosensitive inner shell 200 is at least one of polyethylene, polypropylene, polyvinylidene fluoride and heat-shrinkable rubber materials.

[0046] In the above embodiments, polyethylene, polypropylene, polyvinylidene fluoride and heat-shrinkable rubber materials all have good electrochemical inertness and will not react with the electrolyte or other chemical substances inside the battery, thus avoiding the degradation or damage of battery performance caused by material reactions. Moreover, polyethylene, polypropylene, polyvinylidene fluoride and heat-shrinkable rubber materials will undergo heat-shrinkage deformation when heated to a specific temperature. When the control module triggers the heating module to work and heats the thermosensitive inner shell 200 to the shrinkage temperature, the thermosensitive inner shell 200 will shrink, thereby squeezing the additive sandwich layer 300 to release the electrolyte additive.

[0047] In one embodiment, the control module is a battery management system.

[0048] In the above embodiments, the battery management system (BMS) as the control module has the ability to monitor various key parameters of the battery in real time, such as voltage, current, temperature, state of health value of the battery, etc. Through precise monitoring, the battery management system can comprehensively understand the operating state and performance changes of the battery, providing reliable data support for the management and maintenance of the battery.

[0049] The battery management system intelligently triggers the operation of the heating module according to the comparison result between the detected state of health value of the battery and the preset threshold, realizing the in-situ replenishment of the additive. So that when the health state of the battery drops to a certain extent, it can be automatically maintained and adjusted without manual intervention, improving the intelligence level and user experience of the battery system. At the same time, it also avoids the battery performance loss or damage caused by human judgment errors or operation delays.

[0050] In one embodiment, it further includes a top cover 120. The shapes of the outer shell 100 and the thermosensitive inner shell 200 are both rectangular parallelepiped-shaped, and openings are provided at the same end of the outer shell 100 and the thermosensitive inner shell 200, and the top cover 120 is arranged at the opening of the outer shell 100.

[0051] In the above embodiments, the cuboid-shaped outer shell 100 and the thermosensitive inner shell 200 are designed to make the spatial layout inside the battery more regular and compact, which is beneficial to improving the energy density and integration of the battery. At the same time, it is also beneficial to perform precise positioning and installation during the battery assembly process, ensuring that each component can be closely fitted and reducing space waste. The design of opening openings at one end with the same orientation makes the battery assembly and maintenance processes more convenient. The internal assembly and inspection of the battery can be carried out from the same direction, improving the efficiency of assembly and maintenance.

[0052] On the top surface of the top cover 120, a positive electrode tab 130 and a negative electrode tab 140 are provided. The end portions of the positive electrode tab 130 and the negative electrode tab 140 are respectively connected to the battery cell 110. The positive electrode tab 130 and the negative electrode tab 140 are used to electrically connect the battery to the control module in the external circuit. The top cover 120 is disposed at the opening of the outer shell 100, which provides convenience for the assembly and maintenance of the battery. During battery assembly, components such as the battery cell 110, the thermosensitive inner shell 200, and the additive sandwich layer 300 can be placed into the outer shell 100 through the opening of the top cover 120 for assembly and fixation. During battery maintenance, the interior of the battery can also be quickly inspected and components can be replaced through the opening of the top cover 120, improving the maintainability of the battery. In addition, the design of the top cover 120 can also play a certain sealing role, preventing the leakage of the electrolyte or impurities in the external environment from entering the battery interior, ensuring the normal operation and stable performance of the battery.

[0053] In one embodiment, the material of the outer shell 100 includes at least one of aluminum, aluminum alloy, copper alloy, and stainless steel.

[0054] In the above embodiments, aluminum, aluminum alloy, copper alloy, and stainless steel all have good thermal conductivity, which can effectively conduct the heat generated inside the battery to the external environment, thereby reducing the working temperature of the battery. Good thermal conductivity helps to maintain the battery operating within an appropriate temperature range, avoiding problems such as a decline in battery performance, shortened lifespan, or thermal runaway caused by excessive temperature, and improving the thermal stability and safety of the battery.

[0055] Aluminum, aluminum alloy, copper alloy, and stainless steel all have relatively high mechanical strength and impact resistance, and can withstand various mechanical stresses that the battery may encounter during use, such as vibration and impact. The high strength and impact resistance of the outer shell 100 can effectively protect the structure of the battery cell 110 inside the battery, preventing the battery performance from being damaged or a safety accident from occurring due to external mechanical damage, and improving the reliability and durability of the battery.

[0056] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0057] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A battery, characterized in that, Comprising: A housing, a thermosensitive inner shell, an additive interlayer, a control module, and a heating module; The thermosensitive inner shell is disposed inside the housing; The additive interlayer is disposed between the housing and the thermosensitive inner shell; The control module is used to detect the state of health value of the battery cell, and compare the state of health value of the battery cell with a preset threshold. When the state of health value of the battery cell is less than the preset threshold, the control module drives the heating module to work; The heating module is disposed at the thermosensitive inner shell. The heating module responds to the working instruction of the control module. The heating module heats the thermosensitive inner shell to the shrinkage temperature at which the thermosensitive inner shell shrinks, and lasts for a preset time.

2. The battery according to claim 1, wherein The proportion of the mass of the additive interlayer relative to the mass of the electrolyte in the battery cell is 0.5 - 9%.

3. The battery according to claim 1, characterized in that, The shrinkage temperature of the thermosensitive inner shell is lower than the deformation temperature of the housing.

4. The battery according to claim 1, wherein The shrinkage temperature of the thermosensitive inner shell is lower than the decomposition temperature of the electrolyte.

5. The battery according to claim 1, characterized in that, When the temperature of the thermosensitive inner shell is lower than the shrinkage temperature, the thermosensitive inner shell maintains its original shape.

6. The battery according to claim 1, characterized in that, The material of the thermosensitive inner shell is an electrochemically inert material.

7. The battery according to claim 1, characterized in that, The thermosensitive inner shell is at least one of polyethylene, polypropylene, polyvinylidene fluoride, and heat-shrinkable rubber materials.

8. The battery according to claim 1, characterized in that, The control module is a battery management system.

9. The battery according to claim 1, characterized in that, It further includes a top cover. The shapes of the housing and the thermosensitive inner shell are both rectangular parallelepiped, and openings are provided at one end of the housing and the thermosensitive inner shell facing the same direction. The top cover is disposed at the opening of the housing.

10. The battery according to claim 1, characterized in that, The material of the housing includes at least one of aluminum, aluminum alloy, copper alloy, and stainless steel.

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