Preparation method of anode pole piece of lithium iron phosphate lithium ion battery for large-capacity vehicle

Abstract

The invention relates to a preparation method of an anode pole piece of a lithium iron phosphate lithium ion battery for a large-capacity vehicle. The preparation method comprises the following steps of: (1) placing 86-92% of lithium iron phosphate, 2-4% of a conductive agent, 3-4% of PVDF (polyvinylidene fluoride) and the residual amount of solvent according to weight percentage into a stirrer; and vacuumizing and sufficiently stirring to obtain slurry; (2) coating the slurry on an anode current collection body according to a surface density of 310-320 g / m<2>, and drying to obtain a pole piece; (3) roasting the pole piece and then rolling the pole piece to a certain thickness according to process requirements; (4) splitting the rolled pole piece by using an automatic splitting machine, so as to obtain the pole piece with a desired width; and (5) carrying out die-cutting on the split pole piece, so as to obtain the desired pole piece. The slurry prepared by the invention has good rheological property, consistency and stability; the blanking condition of the pole piece can be greatly improved; the short-circuit condition, the cycle life and the security of the battery can be greatly improved; and the preparation method provided by the invention has a good application prospect.

Description

technical field [0001] The invention belongs to the field of preparation of lithium iron phosphate lithium ion batteries, in particular to a method for preparing a positive pole piece of lithium iron phosphate lithium ion batteries for large-capacity automobiles. Background technique [0002] Today, with the increasing shortage of oil resources and increasingly serious environmental pollution, the harmonious development of energy, resources, environment and human society has increasingly become the focus of social attention. It is seeking to develop alternative energy sources to traditional petrochemical energy, to realize the development of harmless resource industries, and to seek human harmony. Environmental harmony is particularly urgent. In modern society, people's demand for large-capacity and high-power batteries is becoming stronger and stronger, especially for power tools, electric bicycles, motorcycles, automobile power sources and backup power batteries. The curr...

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Problems solved by technology

[0005] However, in the prior art, there is a problem that the produced pole piece stacks are easy to short circuit after being produced due to material loss of the positive pole piece produced in the early stage.