System formula of lithium iron phosphate power battery pole piece difficult-to-permeate liquid and experimental method of lithium iron phosphate power battery pole piece difficult-to-permeate liquid

Abstract

The invention provides a system formula of a lithium iron phosphate power battery pole piece infiltrating solution and an experimental method, and belongs to the technical field of lithium batteries, and the method comprises the following steps: respectively adding LiPF6 into a solvent system with a fixed ratio according to a series of mass ratios at a uniform speed, mixing to prepare LiPF6 mixed solutions with different contents, then measuring the viscosity, the conductivity and the wetting angle, and determining the optimal LiPF6 content; respectively adding LiPF6 into the organic solvent systems with different proportions according to a series of mass ratios at a uniform speed, mixing, controlling the LiPF6 in each mixed solution to be the determined optimal content, measuring the viscosity, the conductivity and the wetting angle, and determining the optimal solvent system proportion; and mixing the determined mixed solution with adjuvants in different proportions, then measuring the viscosity, the conductivity and the wetting angle, and determining the optimal electrolyte system formula. The electrolyte formula system provided by the invention has the advantages of good system compatibility and remarkable improvement effect, and has universality for battery pole pieces of different material systems. In addition, compared with a visual inspection method, a weighing method and other common methods for characterizing the wettability of the electrolyte, the method for measuring the wettability angle by adopting the xenolithlus bubble method has the advantages of simplicity and accuracy.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a system formulation and an experimental method for the impermeable liquid-permeable pole piece of a lithium iron phosphate power battery. Background technique [0002] Lithium iron phosphate batteries still occupy the dominant position of power lithium-ion batteries due to their long life and high safety, especially in the field of energy storage. However, the tap density of the lithium iron phosphate cathode material is small and the capacity space is limited. To further improve the energy density of the lithium iron phosphate power battery, it is one of the more direct solutions to improve the compaction density of the positive / negative pole pieces. However, in order to rapidly increase the capacity of lithium iron phosphate power batteries, some manufacturers blindly increase the compaction density of the positive and negative pole pieces. The microscopic impact is ...

AI Technical Summary

Problems solved by technology

However, auxiliary modified materials may be expensive and difficult to prepare, and if they are directly added to the mature positive / negative electrode material system, the compatibility is poor

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