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DE-212025000118-U1 - Battery cell, battery device, energy storage device, energy storage system and power-consuming device

DE212025000118U1DE 212025000118 U1DE212025000118 U1DE 212025000118U1DE-212025000118-U1

Abstract

Battery cell comprising an electrode assembly, wherein the electrode assembly consists of a cathode foil, an anode foil and a separating film; wherein the anode foil comprises an anode collector and an anode material layer arranged on at least one side of the anode collector, wherein the anode material layer comprises an active anode material, wherein the active anode material comprises graphite coated with amorphous carbon, wherein the graphite coated with amorphous carbon comprises a graphite core and an amorphous carbon coating on the surface of the graphite core, wherein the interlayer spacing of the crystal plane (002) of the amorphous carbon is D1, the interlayer spacing of the crystal plane (002) of the graphite core is D2 and the relationship between D1 and D2 1.0 < D1/D2 ≤ 1.1 is satisfied; wherein the cathode foil comprises a cathode collector and a cathode material layer arranged on at least one side of the cathode collector, wherein the cathode material layer comprises an active cathode material, wherein the active cathode material comprises a carbon-coated lithium iron phosphate material, wherein the ratio of the peak intensity Id of the D-peak to the peak intensity Ig of the G-peak in the Raman spectrum of the carbon-coated lithium iron phosphate material Id/Ig ≤ 1.5.

Assignees

  • CONTEMPORARY AMPEREX TECHNOLOGY CO LTD

Dates

Publication Date
20260513
Application Date
20251226
Priority Date
20250124

Claims (14)

  1. Battery cell comprising an electrode assembly, wherein the electrode assembly consists of a cathode foil, an anode foil and a separating film; wherein the anode foil comprises an anode collector and an anode material layer arranged on at least one side of the anode collector, wherein the anode material layer comprises an active anode material, wherein the active anode material comprises graphite coated with amorphous carbon, wherein the graphite coated with amorphous carbon comprises a graphite core and an amorphous carbon coating on the surface of the graphite core, wherein the interlayer spacing of the crystal plane (002) of the amorphous carbon is D1, the interlayer spacing of the crystal plane (002) of the graphite core is D2 and the relationship between D1 and D2 1.0 < D1/D2 ≤ 1.1 is satisfied; wherein the cathode foil comprises a cathode collector and a cathode material layer arranged on at least one side of the cathode collector, wherein the cathode material layer comprises an active cathode material, wherein the active cathode material comprises a carbon-coated lithium iron phosphate material, wherein the ratio of the peak intensity Id of the D-peak to the peak intensity Ig of the G-peak in the Raman spectrum of the carbon-coated lithium iron phosphate material Id/Ig ≤ 1.5.
  2. Battery cell after Claim 1 , where the ratio of the peak intensity Id of the D-peak to the peak intensity Ig of the G-peak in the Raman spectrum of the carbon-coated lithium iron phosphate material is 0.9 ≤ Id/Ig ≤ 1.3.
  3. Battery cell after Claim 1 or 2 , wherein the anode material layer comprises a first anode material layer and a second anode material layer, wherein the first anode material layer is arranged on at least one side of the anode collector, while the second anode material layer is arranged on a side of the first anode material layer facing away from the anode collector, wherein the ratio of the thickness t 2 of the second anode material layer to the thickness t 1 of the first anode material layer satisfies 2/3 ≤ t 2 /t 1 ≤ 1.5; and/or wherein the porosity of the second anode material layer is greater than the porosity of the first anode material layer.
  4. Battery cell after one of the Claims 1 until 3 , wherein the thickness t1 of the first anode material layer and the thickness t2 of the second anode material layer are each independently selected from 57 µm to 87 µm; and/or wherein the porosity of the first anode material layer and the porosity of the second anode material layer are each independently selected from 25% to 36%.
  5. Battery cell after one of the Claims 1 until 4 , wherein the lithium iron phosphate material comprises one or more dopants of Ti, V, Mg, Zr and Y.
  6. Battery cell after one of the Claims 1 until 5 , where the coating area density of the cathode foil is 19.4 mg/ cm² to 26.7 mg/ cm² .
  7. Battery cell after one of the Claims 1 until 6 , where the density of the cathode material layer is 2.38 mg/ cm² to 2.70 g/ cm³ .
  8. Battery cell after one of the Claims 1 until 7 , wherein the battery cell further comprises an electrolyte solution comprising a solvent, wherein the solvent comprises a cyclic carbonate.
  9. Battery cell after Claim 8 , wherein the solvent comprises ethylene carbonate (EC), optionally comprising 15% to 25% of the mass of the electrolyte solution.
  10. Battery cell after Claim 8 or 9 , wherein the solvent comprises propylene carbonate (PC), optionally comprising 1% to 8% of the mass of the propylene carbonate in the mass of the electrolyte solution.
  11. Battery device comprising several battery cells according to one of the Claims 1 until 10 .
  12. Energy storage device comprising several battery cells according to one of the Claims 1 until 10 or several battery devices after Claim 11 , wherein the battery cells or battery devices are used to store or supply electrical energy.
  13. Energy storage system comprising a power conversion device and an energy storage device according to Claim 12 , wherein the power conversion device is used to electrically connect a power generating device and the energy storage device.
  14. Power consumption device comprising a battery cell according to one of the Claims 1 until 10 , a battery device according to Claim 11 , an energy storage device according to Claim 12 or an energy storage system according to Claim 13 , wherein the battery cell or battery device is used to store or supply electrical energy.

Description

CROSS-REFERENCE TO RELATED REGISTRATION The present application is based on the CN registration no. 202510117678.6 , submitted on January 24, 2025, the contents of which are hereby incorporated in full by reference into the present application. TECHNICAL AREA The present application relates to the technical field of the battery cell, in particular a battery cell, a battery device, an energy storage device, an energy storage system and a power-consuming device. STATE OF THE ART Energy storage batteries form the core component of energy storage systems and primarily utilize chemical reactions for energy storage. Energy storage requires battery structures with high capacity, long lifespan, high safety, and high energy efficiency. Currently, market demands regarding the lifespan of energy storage products are becoming increasingly stringent. CONTENT OF THE PRESENT INVENTION To solve the problem of the cycle life of battery cells, a first embodiment of the present application provides a battery cell comprising an electrode assembly, wherein the electrode assembly consists of a cathode foil, an anode foil and a separating film, wherein the anode foil comprises an anode collector and an anode material layer arranged on at least one side of the anode collector, wherein the anode material layer comprises an active anode material, wherein the active anode material comprises graphite coated with amorphous carbon, wherein the graphite coated with amorphous carbon comprises a graphite core and an amorphous carbon coating on the surface of the graphite core, wherein the interlayer spacing of the crystal plane (002) of the amorphous carbon is D1, the interlayer spacing of the crystal plane (002) of the graphite core is D2 and the relationship between D1 and D2 1.0 < D1/D2 ≤ 1.1 satisfies; wherein the cathode foil comprises a cathode collector and a cathode material layer arranged on at least one side of the cathode collector, wherein the cathode material layer comprises an active cathode material, wherein the active cathode material comprises a carbon-coated lithium iron phosphate material, wherein the ratio of the peak intensity Id of the D-peak to the peak intensity Ig of the G-peak in the Raman spectrum of the carbon-coated lithium iron phosphate material Id/Ig ≤ 1.5. The battery cell of the present application comprises graphite coated with amorphous carbon within the anode foil. An amorphous carbon layer is formed on the surface of the graphite particles, and the surface of the highly graphitized graphite material is coated with amorphous carbon with a low degree of graphitization to obtain a two-layer carbon material. This enables the highly graphitized graphite to exhibit both a high discharge capacity and excellent C-rate performance. The interlayer spacing of the amorphous carbon material is larger than that of graphite, thus improving lithium-ion diffusion within the material. This effect is analogous to the formation of a buffer layer for lithium ions on the graphite surface, thereby improving the high-current charge/discharge performance of the graphite material. Simultaneously, by controlling the difference between the interlayer spacing of the amorphous carbon and that of the graphite core—specifically, by maintaining D1/D2 ≤ 1.1—the resistance to lithium ion egress from the amorphous carbon coating layer is reduced. Furthermore, the contact of the amorphous carbon with the solvent prevents delamination of the graphite layer caused by the co-incorporation of solvent molecules, thus expanding the range of electrolyte systems and improving the cycle stability of the electrode material. The degree of order of graphite coated with amorphous carbon is characterized by the ratio of the interlayer spacing D1 of the crystal plane (002) of the amorphous carbon to the interlayer spacing D2 of the crystal plane (002) of the graphite core. D1/D2 within a specific The area ensures the stability of the graphite interlayer structure while simultaneously reducing the lithium-ion diffusion resistance, thus facilitating lithium-ion storage and removal during charge and discharge cycles. The battery cell of the present application also incorporates carbon-coated lithium iron phosphate material in the cathode foil. The carbon coating effectively improves the surface electron contact within the lithium iron phosphate material, enhancing its electronic conductivity and thereby increasing its C-rate and cycle performance. If the carbon coating layer exhibits a high degree of graphitization, the conductivity of the carbon-coated lithium iron phosphate material can be further increased, while simultaneously suppressing reactions between the carbon coating layer and the electrolyte solution. Consequently, the simultaneous integration of the aforementioned active anode material and the active cathode material into the battery reduces the consumption of active lithium during the battery cycle process and improves the battery's kinetic