A kind of positive electrode slurry of lithium ion battery and its preparation method and application

Abstract

The invention discloses a lithium ion battery positive electrode slurry and its preparation method and application. A viscosity reducer is introduced into the positive electrode slurry, and the viscosity reducer can be adsorbed on the surface of lithium iron phosphate active material to effectively regulate the surface space of lithium iron phosphate nanoparticles. The steric hindrance and Zeta potential prevent the aggregation and settlement of the lithium iron phosphate active material, thereby suppressing the viscosity rebound and even the gel problem of the positive electrode slurry after standing still. The present invention pre-dries the lithium iron phosphate active material and the first conductive agent Adding a viscosity reducer can effectively regulate the steric hindrance and Zeta potential of the surface of lithium iron phosphate nanoparticles, prevent the aggregation and sedimentation of lithium iron phosphate active materials, thereby inhibiting the viscosity rebound and even gel problems of the positive electrode slurry after standing, and the iron phosphate The pre-dry mixing of the lithium active material and the first conductive agent can form a structure in which the carbon black uniformly covers the active material, which is beneficial to the conductivity of the positive lithium iron phosphate, reduces internal resistance, and improves electrochemical performance.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and relates to a positive electrode slurry for lithium ion batteries, a preparation method and application thereof. Background technique [0002] Lithium-ion batteries have outstanding advantages such as high energy density, high output power density, long cycle life, extremely low self-discharge rate, wide temperature range, and short charging time. Not only has it successfully replaced lead-acid batteries in the field of power batteries, but it also plays an important role in the fields of national defense, military, and aerospace. It is also gradually replacing nickel-metal hydride and lead-acid batteries to achieve iterative upgrades of equipment. [0003] The fields of national defense, military and aerospace generally require lithium-ion batteries to have ultra-low temperature discharge performance under the premise of ensuring excellent cycle performance, extremely low self-d...

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Problems solved by technology

[0005] However, there is a significant problem with the above two slurry systems and homogenization processes for nanoscale lithium iron phosphate, especially with a particle size below 100nm, that is, the viscosity of the prepared slurry will rebound greatly after standing still, and even gel will appear. / Jelly phenomenon, not conducive to subsequent application

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