A kind of preparation method of lithium-ion battery cathode with high rate performance

Abstract

The invention provides a preparation method of a lithium ion battery positive electrode with high rate performance, the positive electrode comprising a current collector and a first active material layer, a second active material layer and a passivation conductive layer which are located on the current collector, the first active material layer comprising lithium nickel oxide, the second active material layer comprising doped lithium manganese cobalt oxide and doped lithium iron phosphate, the passivation conductive layer comprising inorganic oxide particles and an organic conductive polymer.The preparation method of the invention obtains a positive electrode with high conductivity, stable structure and good cycling performance in a high-rate environment by controlling the production process.

Description

technical field

[0001] The invention relates to the technical field of lithium ion batteries, in particular to a method for preparing a positive electrode of a lithium ion battery with high rate performance. Background technique

[0002] With the gradual increase in the energy density, output power and cycle life requirements of electric tools for batteries, the positive electrode composed of a single active material can no longer meet the needs of electric tools, and batteries with mixed positive electrode materials have become the focus of research and development. , different mixing technologies and different structural designs for active materials are required. Although the current mixed materials can provide high output power and energy density, the internal resistance of the pole piece is biased due to excessive compression of the pole piece. Large, the heat release is obvious at high rates, and the cycle life of the battery is deteriorated due to the dissolution of th...

Examples

Embodiment 1

[0028] 1), providing lithium nickel oxide, the molecular formula of the lithium nickel oxide is LiNi 0.7 co 0.29 Nb 0.01 o 2 ; The average particle diameter of the lithium nickel oxide is 500nm, and the aspect ratio is 1.0, the lithium nickel oxide and acetylene black are mixed with a mass ratio of 100:3, placed in a ball mill jar, and heated at a speed of 200r / min Speed ​​ball milling for 6h;

[0029] 2), add the solvent into the first vacuum stirred tank, add PVDF into the first vacuum stirred tank, stir in vacuum for 2 hours, then add sodium carboxymethyl cellulose, stir in vacuum for 1 hour, add the product of step 1, and stir in vacuum 4h, adding carbon nanofibers with a length of 5 microns, and stirring in a vacuum for 4h to obtain the first slurry, the solid content of the first slurry is 50%, wherein the mass ratio, the lithium nickel oxide: acetylene black: PVDF : sodium carboxymethyl cellulose: carbon nanofibers=100:3:4:2:5;

[0030] 3), providing doped lithium ...

Embodiment 2

[0035] 1), providing lithium nickel oxide, the molecular formula of the lithium nickel oxide is LiNi 0.82 co 0.15 Ti 0.03 o 2 The average particle diameter of described lithium nickel oxide is 2000nm, aspect ratio is 1.2, described lithium nickel oxide and acetylene black are mixed with the mass ratio of 100:6, are placed in ball mill tank, with 300r / min Speed ​​ball milling for 8 hours;

[0036] 2), add the solvent into the first vacuum stirred tank, add PVDF into the first vacuum stirred tank, stir in vacuum for 4 hours, then add sodium carboxymethylcellulose, stir in vacuum for 2 hours, add the product of step 1, and stir in vacuum 6h, add carbon nanofibers with a length of 20 microns, and stir in vacuum for 6h to obtain the first slurry, the solid content of the first slurry is 54%, wherein the mass ratio, the lithium nickel oxide: acetylene black: PVDF : sodium carboxymethyl cellulose: carbon nanofibers=100:6:8:4:8;

[0037] 3), providing doped lithium manganese coba...

Embodiment 3

[0042] 1), providing lithium nickel oxide, the molecular formula of the lithium nickel oxide is LiNi 0.7 co 0.29 Nb 0.01 o 2 ; The average particle diameter of the lithium nickel oxide is 1000nm, and the aspect ratio is 1.2, the lithium nickel oxide is mixed with acetylene black at a mass ratio of 100:5, placed in a ball mill jar, and heated at a speed of 300r / min Speed ​​ball milling for 8 hours;

[0043] 2), add the solvent into the first vacuum stirred tank, add PVDF into the first vacuum stirred tank, stir in vacuum for 4 hours, then add sodium carboxymethylcellulose, stir in vacuum for 2 hours, add the product of step 1, and stir in vacuum 6h, add carbon nanofibers with a length of 10 microns, and stir in vacuum for 6h to obtain the first slurry, the solid content of the first slurry is 52%, wherein the mass ratio, the lithium nickel oxide: acetylene black: PVDF : sodium carboxymethyl cellulose: carbon nanofibers=100:5:6:3:7;

[0044] 3), providing doped lithium mang...

technical field

[0001] The invention relates to the technical field of lithium ion batteries, in particular to a method for preparing a positive electrode of a lithium ion battery with high rate performance. Background technique

[0002] With the gradual increase in the energy density, output power and cycle life requirements of electric tools for batteries, the positive electrode composed of a single active material can no longer meet the needs of electric tools, and batteries with mixed positive electrode materials have become the focus of research and development. , different mixing technologies and different structural designs for active materials are required. Although the current mixed materials can provide high output power and energy density, the internal resistance of the pole piece is biased due to excessive compression of the pole piece. Large, the heat release is obvious at high rates, and the cycle life of the battery is deteriorated due to the dissolution of th...

Examples

Embodiment 1

[0028] 1), providing lithium nickel oxide, the molecular formula of the lithium nickel oxide is LiNi 0.7 co 0.29 Nb 0.01 o 2 ; The average particle diameter of the lithium nickel oxide is 500nm, and the aspect ratio is 1.0, the lithium nickel oxide and acetylene black are mixed with a mass ratio of 100:3, placed in a ball mill jar, and heated at a speed of 200r / min Speed ​​ball milling for 6h;

[0029] 2), add the solvent into the first vacuum stirred tank, add PVDF into the first vacuum stirred tank, stir in vacuum for 2 hours, then add sodium carboxymethyl cellulose, stir in vacuum for 1 hour, add the product of step 1, and stir in vacuum 4h, adding carbon nanofibers with a length of 5 microns, and stirring in a vacuum for 4h to obtain the first slurry, the solid content of the first slurry is 50%, wherein the mass ratio, the lithium nickel oxide: acetylene black: PVDF : sodium carboxymethyl cellulose: carbon nanofibers=100:3:4:2:5;

[0030] 3), providing doped lithium ...

Embodiment 2

[0035] 1), providing lithium nickel oxide, the molecular formula of the lithium nickel oxide is LiNi 0.82 co 0.15 Ti 0.03 o 2 The average particle diameter of described lithium nickel oxide is 2000nm, aspect ratio is 1.2, described lithium nickel oxide and acetylene black are mixed with the mass ratio of 100:6, are placed in ball mill tank, with 300r / min Speed ​​ball milling for 8 hours;

[0036] 2), add the solvent into the first vacuum stirred tank, add PVDF into the first vacuum stirred tank, stir in vacuum for 4 hours, then add sodium carboxymethylcellulose, stir in vacuum for 2 hours, add the product of step 1, and stir in vacuum 6h, add carbon nanofibers with a length of 20 microns, and stir in vacuum for 6h to obtain the first slurry, the solid content of the first slurry is 54%, wherein the mass ratio, the lithium nickel oxide: acetylene black: PVDF : sodium carboxymethyl cellulose: carbon nanofibers=100:6:8:4:8;

[0037] 3), providing doped lithium manganese coba...

Embodiment 3

[0042] 1), providing lithium nickel oxide, the molecular formula of the lithium nickel oxide is LiNi 0.7 co 0.29 Nb 0.01 o 2 ; The average particle diameter of the lithium nickel oxide is 1000nm, and the aspect ratio is 1.2, the lithium nickel oxide is mixed with acetylene black at a mass ratio of 100:5, placed in a ball mill jar, and heated at a speed of 300r / min Speed ​​ball milling for 8 hours;

[0043] 2), add the solvent into the first vacuum stirred tank, add PVDF into the first vacuum stirred tank, stir in vacuum for 4 hours, then add sodium carboxymethylcellulose, stir in vacuum for 2 hours, add the product of step 1, and stir in vacuum 6h, add carbon nanofibers with a length of 10 microns, and stir in vacuum for 6h to obtain the first slurry, the solid content of the first slurry is 52%, wherein the mass ratio, the lithium nickel oxide: acetylene black: PVDF : sodium carboxymethyl cellulose: carbon nanofibers=100:5:6:3:7;

[0044] 3), providing doped lithium mang...

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