High capacity lithium iron phosphate power cell and production technique thereof

Abstract

The invention relates to a high-capacity iron phosphate lithium power battery, which is characterized in that the anode material uses the iron phosphate lithium; an anode current collector uses the aluminum foil; a conductive agent uses the superconducting carbon black and the conductive graphite; the anode material binder uses the polyvinylidene fluorine; the cathode material uses the natural graphite or the artificial graphite; the cathode current collector uses copper foil; the conductive agent uses the superconducting carbon black and the conductive graphite; and the cathode material binder uses the polyvinylidene fluorine or the sodium carboxymethylcellulose and the styrene butadiene rubber. The invention also discloses a processing technology of the high capacity iron phosphate lithium power battery, comprising the following step: matching ingredients, coating, baking, rolling, processing slice, baking, staking, assembling upper cover , baking, liquid injection, formation and partial volume. The invention adopts a stacking type, and has simple processing technology, compact battery structure and stable performance; thus, the battery capacity is greatly improved. The invention has an advantage of providing the lithium ion secondary battery of a driving energy source to the small and medium sized electric tools, such as the household electric appliance, the electric bicycle, the electric motorcycle and the electric automobile.

Description

technical field [0001] The invention relates to a battery, in particular to a high-capacity lithium iron phosphate power battery and a manufacturing process thereof. Background technique [0002] With the development of the economy and the improvement of people's living standards, people's demand for high-energy density and large-capacity batteries is becoming more and more intense. Lithium-ion batteries have the best performance among the several batteries that can be used for power tools. Lithium-ion batteries are different from ordinary acid batteries in that they have the characteristics of high voltage, high specific energy, long cycle life, and low self-discharge rate. However, for lithium-ion batteries that have been used in mobile phones, notebook computers and other fields, how to make them bigger has always been a technical problem that plagues the development of power batteries. LiCoO 2 It is the earliest positive electrode material used in commercial lithium-io...

AI Technical Summary

Problems solved by technology

It is expected that spinel LiMn 2 o 4 Can rely on its cheap and relatively LiCoO 2 The advantages of safety play a role in large-capacity batteries, but a good solution has not been found for its shortcomings of low capacity and poor high-temperature cycle performance, and it has not been widely promoted in actual batteries.

[0005] Although lithium iron phosphate power battery has a series of incomparable advantages of other materials, it also has some shortcomings, mainly in: 1. Pure LiFePO 4 Poor electrical conductivity and lithium ion diffusion performance, resulting in poor battery high current discharge performance; 2. LiFePO 4 The bulk density and tap density are relatively low, and it is not easy to process, which leads to difficulty in the coating of positive electrode slurry in the production process, and the battery capacity is low