CN-121983605-A - High-power discharge lithium-chromium-based oxide battery and manufacturing method thereof

Abstract

The invention belongs to the technical field of lithium primary battery thermal management, and particularly discloses a high-power discharge lithium-chromium-based oxide battery and a manufacturing method thereof. The battery includes a plurality of cells, a battery housing, and a sheet-like thermal management interlayer disposed between the cells and/or between the cells and the battery housing. The thermal management interlayer is a graphene skeleton phase change composite material and is composed of a three-dimensional porous graphene network and a composite phase change material filled in pores of the network. The interlayer with the high heat conduction and high heat storage functions is integrated, so that heat can be actively and rapidly absorbed and homogenized when the battery discharges at high power, the temperature rise of the battery pack is effectively inhibited, local hot spots are eliminated, continuous and stable high power output is realized, and the safety and reliability of a battery system are obviously improved.

Inventors

• ZHANG HONGMEI
• YAO DEMING
• XU XING
• YUAN ZAIFANG
• CHEN SHAOMIN
• WANG GUOJIANG
• WANG QINGJIE
• YU HUA

Assignees

• 贵州梅岭电源有限公司

Dates

Publication Date

20260505

Application Date

20260210

Claims (10)

1. 1. A flaky thermal management interlayer is characterized by being mainly a graphene skeleton phase-change composite material with a flaky structure, wherein the graphene skeleton phase-change composite material is composed of a three-dimensional porous graphene network and composite phase-change materials filled in pores of the network.
2. 2. The sheet-like thermal management interlayer of claim 1, wherein said thermal management interlayer is a multi-layer composite flexible sheet, further comprising: a porous polymer interface layer covering upper and lower surfaces of the sheet-shaped thermal management interlayer; and the flexible sealing layer is coated on the periphery of the sheet.
3. 3. The sheet-like thermal management interlayer of claim 1 or 2, wherein the composite phase change material comprises a main phase change component having a phase change temperature of 50 ℃ to 90 ℃ and a thermally conductive reinforcing nanofiller.
4. 4. The sheet thermal management interlayer of claim 2, wherein the graphene skeleton has a porosity of 90% -93%.
5. 5. The sheet-like thermal management interlayer of claim 1, wherein the sheet-like thermal management interlayer has an in-plane thermal conductivity of 15: 15W/(m.k), a thickness of 0.5 mm to 10.0 mm, and a flex radius of 20mm or less.
6. 6. The thermal management interlayer in sheet form of claim 1 wherein said phase change material comprises a major phase change component selected from at least one of a high purity paraffin wax, a fatty acid, or an alkane eutectic mixture.
7. 7. A high power discharge lithium-chromium-based oxide battery comprising a plurality of cells and a battery housing, characterized in that it further comprises the sheet-like thermal management interlayer of any of claims 1, 2, 4-6, which is disposed between adjacent cells and/or between the cells and the battery housing.
8. 8. The battery of claim 7, wherein thermally conductive silicone grease is also filled between adjacent cells.
9. 9. The battery of claim 7, wherein the contact area of the sheet-form thermal management interlayer to the cell side is greater than 80%.
10. 10. A method of manufacturing a high power discharge lithium-chromium-based oxide battery according to claim 7, comprising the steps of: (1) Preparing a graphene skeleton, namely taking graphene hydrogel with high concentration and uniform dispersion as a raw material, taking deionized water as a solvent, and stirring at a high speed of 2000-3000 r/min for 60-150 min to obtain uniform and stable diluted graphene hydrogel; (2) The preparation method comprises the steps of preparing a flaky graphene skeleton phase change material, namely placing the phase change material into a device, filling the melted composite phase change material into pores of the skeleton through vacuum impregnation at 90-120 ℃, and carrying out hot-pressing reduction treatment to obtain the flaky material, wherein the temperature of the hot-pressing reduction treatment is 150-250 ℃ and the pressure is 5-20 MPa; (3) The battery module is integrated, namely the sheet material obtained in the step (2) is cut and then attached to the preset position of the single battery, and the battery module is assembled; (4) System integration, namely, the battery module is installed in a battery shell and packaged.

Description

High-power discharge lithium-chromium-based oxide battery and manufacturing method thereof Technical Field The invention relates to the technical field of lithium primary batteries, in particular to a high-power discharge lithium-chromium-based oxide battery and a manufacturing method thereof, and the battery is particularly suitable for high-energy density application scenes requiring long-time and high-current discharge. Background As a positive electrode material, the lithium-chromium-based oxide (such as Cr 8O21 and derivatives thereof) has high working voltage and good structural stability. However, the intrinsic electron conductivity and ion diffusion coefficient of the material are limited, so that the polarization voltage of the material is obviously increased when the material is discharged at a high multiplying power (more than or equal to 1C), and the actual output power is sharply reduced and serious Joule heat accumulation is accompanied. In the application scene of the battery pack, the series/parallel operation of a plurality of batteries can further amplify the heat accumulation effect, and the following problems are caused: 1. Power decay and interruption-local overheating triggers the thermal protection mechanism of the Battery Management System (BMS), forcing a limit or interrupt discharge, failing to meet sustained high power demands. 2. Thermal runaway risk of a single cell may cause adjacent cells to overheat through heat conduction and radiation, leading to catastrophic failure. 3. The capacity attenuation rate and aging mode of each single battery are inconsistent due to uneven temperature distribution in the battery pack, and the overall service life is shortened. The existing thermal management technology is mostly focused on active heat dissipation schemes such as liquid cooling, air cooling and the like or wrapped by using traditional phase change materials. The method has obvious limitations that an active heat dissipation system has high energy consumption and complex structure, and the traditional phase change material has low heat conductivity coefficient, cannot be quickly soaked, has poor contact with a curved surface of a battery and has high thermal resistance. More importantly, most of the existing methods are passive in response, cannot be dynamically coupled with the electrochemical state and power requirements of the battery, and are difficult to maximize power output while suppressing temperature rise. Therefore, there is a need to develop a new battery pack solution with efficient thermal management, adaptive power regulation and structural reliability to fully release the high power potential of lithium-chromium-based oxide cells. Disclosure of Invention The invention aims to solve the technical problem of overcoming the defects of the prior art and providing a lithium-chromium-based oxide battery pack capable of realizing active and efficient heat management and guaranteeing continuous high-power discharge and a manufacturing method thereof. In order to achieve the purpose, the invention adopts the following technical scheme that the sheet-shaped heat management interlayer is mainly a graphene skeleton phase-change composite material with a sheet-shaped structure, wherein the graphene skeleton phase-change composite material is composed of a three-dimensional porous graphene network and composite phase-change materials filled in pores of the network. The three-dimensional graphene network provides high heat conduction paths and structural support to form an ultra-fast in-plane thermal diffusion path, and the phase change material is subjected to solid-liquid phase change in a battery working temperature rise range (such as 50-90 ℃) to absorb and store a large amount of latent heat. Preferably, as an improvement, the sheet-shaped thermal management interlayer is a multilayer composite flexible sheet, and further comprises: a porous polymer interface layer covering upper and lower surfaces of the sheet-shaped thermal management interlayer; and the flexible sealing layer is coated on the periphery of the sheet. The sheet-shaped heat management interlayer is designed into a multi-layer composite flexible structure and comprises a core functional layer, a porous polymer interface layer and a flexible sealing layer from inside to outside, and has the characteristics of high heat conduction, high heat storage, flexible lamination and corrosion resistance. Preferably, as an improvement, the composite phase change material comprises a main phase change component with a phase change temperature of 50-90 ℃ and a heat conduction reinforcing nano filler. The temperature range is slightly higher than the normal working temperature of the battery but lower than the safety pre-warning temperature, so that the phase-change material can timely start the heat absorption function when the temperature rises due to power discharge. Preferably, as an improvement, the mass fraction of th