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DE-212025000098-U1 - Battery cell, battery device, power-consuming device

DE212025000098U1DE 212025000098 U1DE212025000098 U1DE 212025000098U1DE-212025000098-U1

Abstract

Battery cell, including: a case; and an electrode arrangement located within the housing, wherein the electrode arrangement comprises a positive electrode sheet, a negative electrode sheet and a separator, the separator being arranged between the positive electrode sheet and the negative electrode sheet, where the positive electrode sheet comprises a positive electrode current collector and a positive electrode film layer located on at least one side of the positive electrode current collector, wherein the positive electrode film layer comprises a positive electrode active material and has a particle size distribution (Dv90 - Dv10)/Dv50 of the positive electrode active material of 1 to 1.5; and the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer located on at least one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material, the negative electrode active material comprising a silicon-based material and a carbon-based material, wherein the average particle size of the silicon-based material is 2 µm to 10 µm and the mass fraction of the element Si in the negative electrode film layer is 1% to 10%.

Assignees

  • CONTEMPORARY AMPEREX TECHNOLOGY CO LTD

Dates

Publication Date
20260513
Application Date
20250710
Priority Date
20250710

Claims (20)

  1. Battery cell comprising: a housing; and an electrode arrangement located within the housing, the electrode arrangement comprising a positive electrode sheet, a negative electrode sheet, and a separator, the separator being arranged between the positive electrode sheet and the negative electrode sheet, whereby the positive electrode sheet comprises a positive electrode current collector and a positive electrode film layer located on at least one side of the positive electrode current collector, the positive electrode film layer comprising a positive electrode active material and having a particle size distribution (Dv90 - Dv10)/Dv50 of the positive electrode active material of 1 to 1.5; and the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer located on at least one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material, the negative electrode active material comprising a silicon-based material and a carbon-based material, wherein the average particle size of the silicon-based material is 2 µm to 10 µm and the mass fraction of the element Si in the negative electrode film layer is 1% to 10%.
  2. Battery cell after Claim 1 , wherein the particle size distribution (Dv90 - Dv10)/Dv50 of the positive electrode active material is 1.2 to 1.4; and/or the mass fraction of the element Si in the negative electrode film layer is 1% to 5%.
  3. Battery cell after Claim 1 or 2 , wherein the porosity of the positive electrode film layer is 13% to 20%; and/or the porosity of the negative electrode film layer is 20% to 35%.
  4. Battery cell after one of the Claims 1 until 3 , where the volume distribution particle size Dv50 of the positive electrode active material is 2 µm to 7 µm.
  5. Battery cell after one of the Claims 1 until 4 , wherein the positive electrode active material comprises a lithium transition metal oxide with single-crystal morphology and the total area of the lithium transition metal oxide with single-crystal morphology is 60% to 100% of the total area of the positive electrode active material.
  6. Battery cell after one of the Claims 1 until 5 , wherein the positive electrode active material comprises a lithium transition metal oxide, wherein the lithium transition metal oxide comprises element Ni, wherein the molar fraction of element Ni in transition metal elements of the lithium transition metal oxide is greater than 80%.
  7. Battery cell after one of the Claims 1 until 6 , wherein the positive electrode active material comprises a lithium transition metal oxide, wherein the lithium transition metal oxide comprises element Ni and element Co, wherein the content of element Co in a surface layer region of the lithium transition metal oxide is higher than the content of element Co in a core region of the lithium transition metal oxide; or the positive electrode active material comprises a lithium transition metal oxide, wherein the lithium transition metal oxide comprises element Ni and element Mn, wherein the content of element Mn in the surface layer region of the lithium transition metal oxide is lower than the content of element Mn in the core region of the lithium transition metal oxide; or the positive electrode active material comprises a lithium transition metal oxide, wherein the lithium transition metal oxide comprises element Ni, element Co and element Mn, wherein the content of element Co in the surface layer region of the lithium transition metal oxide is higher than the content of element Co in the core region of the lithium transition metal oxide and the content of element Mn in the surface layer region of the lithium transition metal oxide is lower than the content of element Mn in the core region of the lithium transition metal oxide, wherein the surface layer region of the lithium transition metal oxide is a region extending radially inwards by 100 nm from the outermost particle surface and the core region of the lithium transition metal oxide is a region extending radially outwards by 300 nm from the particle center.
  8. Battery cell after one of the Claims 1 until 7 , wherein the positive electrode active material comprises a lithium transition metal oxide, wherein the lithium transition metal oxide comprises element Ni and a doping element, wherein the doping element comprises a cationic doping element and/or an anionic doping element, wherein the cationic doping element comprises one or more of Al, Y, Zr, Zn, Cr, Mg, V, Ti and B and the anionic doping element comprises one or more of N, F, S and Cl.
  9. Battery cell after one of the Claims 1 until 8 , where the degree of lithium nickel disorder of the positive electrode active material is less than 3%.
  10. Battery cell after one of the Claims 1 until 9 , wherein the positive electrode film layer comprises a conductive medium of the positive electrode, wherein the mass fraction of the conductive medium of the positive electrode in the positive electrode film layer is 0.5% to 2.5%.
  11. Battery cell after Claim 10 , wherein the conductive medium of the positive electrode comprises one or more of carbon nanotubes, carbon black, acetylene carbon black, carbon fibers and graphene, wherein the carbon nanotubes comprise one or more of single-walled carbon nanotubes, thin-walled carbon nanotubes and multi-walled carbon nanotubes.
  12. Battery cell after Claim 10 , wherein the conductive medium of the positive electrode comprises carbon nanotubes, wherein at least some of the carbon nanotubes are located on the surface of the positive electrode active material.
  13. Battery cell after one of the Claims 10 until 12 , wherein the conductive medium of the positive electrode comprises an agglomerated conductive medium of the positive electrode, wherein the number density of the agglomerated conductive medium of the positive electrode in the positive electrode film layer is 1 to 15 per 1000 µm 2 .
  14. Battery cell after Claim 13 , wherein the number density of the agglomerated conductive medium of the positive electrode in the positive electrode film layer is 4 to 12 per 1000 µm 2 .
  15. Battery cell after Claim 13 or 14 , wherein the agglomerated conductive medium of the positive electrode satisfies the condition that a maximum value of the distance between any two points on the circumference is greater than or equal to 1 µm; and/or the porosity of the agglomerated conductive medium of the positive electrode is 30% to 65%; and/or the agglomerated conductive medium of the positive electrode comprises carbon nanotubes.
  16. Battery cell after Claim 15 , wherein the agglomerated conductive medium of the positive electrode also comprises one or more carbon black and acetylene black.
  17. Battery cell after one of the Claims 1 until 16 , wherein the negative electrode active material meets one or more of the following conditions (1) to (5): (1) the silicon-based material comprises one or more of elemental silicon, silicon-carbon material, silicon oxide, silicon nitride and silicon alloy material; (2) the carbon-based material comprises one or more of natural graphite, synthetic graphite, soft carbon, hard carbon and mesophase carbon microspheres; (3) the average particle size of the carbon-based material is 14 µm to 22 µm; (4) the volume distribution particle size Dv50 of the negative electrode active material is 11 µm to 20 µm; (5) the particle size distribution (Dv90 - Dv10)/Dv50 of the negative electrode active material is 1.3 to 1.7.
  18. Battery cell after one of the Claims 1 until 17 , wherein the negative electrode film layer comprises a first negative electrode film layer located away from the negative electrode current collector and a second negative electrode film layer located near the negative electrode current collector, wherein the first negative electrode film layer comprises a first negative electrode active material and the second negative electrode film layer comprises a second negative electrode active material, wherein the first negative electrode active material comprises a first carbon-based material and a first silicon-based material, and the second negative electrode active material comprises a second carbon-based material and the The second negative electrode film layer does not contain the element Si, or the second negative electrode active material comprises a second carbon-based material and a second silicon-based material, and the mass fraction of the element Si in the first negative electrode film layer is greater than the mass fraction of the element Si in the second negative electrode film layer.
  19. Battery cell after Claim 18 , wherein the mass fraction of element Si in the first negative electrode film layer is 1% to 11%; and/or the mass fraction of element Si in the second negative electrode film layer is 0% to 5%.
  20. Battery cell after Claim 18 or 19 , wherein the volume distribution particle size Dv50 of the first negative electrode active material is smaller than the volume distribution particle size Dv50 of the second negative electrode active material.

Description

Technical field The present disclosure relates to a battery cell, a battery device and a power-consuming device. State of the art With the widespread adoption of lithium-ion battery cells in recent years, the energy density of existing lithium-ion battery cells using graphite as the negative electrode active material can no longer meet increasing technical demands. Silicon-based materials have emerged as candidates for new negative electrode active materials due to their moderate lithiation potential and high theoretical specific capacity. However, silicon-based materials exhibit a significant problem of volume expansion during cyclic charging and discharging, and it is difficult to form a stable solid electrolyte interface film (SEI film), resulting in a rapid decline in the cycle capacity of the lithium-ion battery cell. Disclosure of the invention The present disclosure provides a battery cell, a battery device and a power-consuming device, wherein the battery cell can have both a high energy density and good cycle performance. According to a first aspect, the present disclosure provides a battery cell comprising a housing and an electrode arrangement, wherein the electrode arrangement is located within the housing, the electrode arrangement comprising a positive electrode sheet, a negative electrode sheet and a separator, the separator being located between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet comprising a positive electrode current collector and a positive electrode film layer located on at least one side of the positive electrode current collector, the positive electrode film layer comprising a positive electrode active material and having a particle size distribution (Dv90 - Dv10)/Dv50 of the positive electrode active material of 1 to 1.5; and the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer located on at least one side of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material, wherein the negative electrode active material comprises a silicon-based material and a carbon-based material, wherein the average particle size of the silicon-based material is 2 µm to 10 µm and the mass fraction of the element Si in the negative electrode film layer is 1% to 10%. By adjusting the composition of the silicon-containing negative electrode sheet, the present disclosure enables the silicon-containing negative electrode sheet to provide a higher capacity while simultaneously exhibiting a lower volume expansion. However, the volume expansion of the silicon-containing negative electrode sheet does not disappear, and thus continues to affect the electrolyte solution wettability and fluid retention capacity of the separator and the positive electrode sheet. The present disclosure further enables the positive electrode active material to have a suitable particle size distribution, which can fully exploit the advantage of the high capacity of the silicon-containing negative electrode sheet while effectively reducing the adverse effects of the volume expansion of the silicon-containing negative electrode sheet on the electrolyte solution wettability and fluid retention capacity of the positive electrode film layer. This reduces the decrease in the cycle capacity of the battery cell, allowing the battery cell to exhibit both high energy density and good cycle performance. In some embodiments, the particle size distribution (Dv90 - Dv10)/Dv50 of the positive electrode active material is 1.2 to 1.4. If the particle size distribution (Dv90 - Dv10)/Dv50 of the positive electrode active material is within the above range, this can result in the positive electrode film layer having a high compaction density, thus giving the battery cell a high energy density. It can also result in the positive electrode film layer having high porosity and a large pore structure, which contributes to good electrolyte solution wettability and fluid retention capacity. This, in turn, helps to mitigate the adverse effects of the volume expansion of the silicon-containing negative electrode sheet on the electrolyte. to reduce the lyte solution wettability and fluid retention capacity of the positive electrode film layer, and contributes to the positive electrode film layer having a good electrolyte solution passage path in the thickness direction, making the problem of interruption of the electrolyte solution passage path less likely, and at the same time can also reduce the problem of particle breakage of the positive electrode active material. In some embodiments, the mass fraction of the element Si in the negative electrode film layer is 1% to 5%. In some embodiments, the porosity of the positive electrode film layer is 13% to 20%. This can result in the battery cell having both a high energy density and good cycle performance. In some embodiments, the p