Preparation method of ultralow-temperature high-rate type lithium ion cell

Abstract

The invention relates to a preparation method of an ultralow-temperature high-rate type lithium ion cell. The preparation method of the ultralow-temperature high-rate type lithium ion cell provided by the invention comprises the following steps of: (A) uniformly mixing lithium cobalt oxide, an electric conduction agent, PVDF (polyvinylidene fluoride) or PVDF / HFP (hexafluoropropylene) by adopting NMP(nuclear matrix protein) as a dissolvant so as to prepare positive pole slurry; (B) uniformly spraying the positive pole slurry on a positive pole current collector by utlizing an atomization spray gun, and drying, rolling and cutting pieces to form a positive pole piece; (C) uniformly mixing a negative pole material, the electric conduction agent, the PVDF or PVDF / HFP by adopting the NMP as the dissolvant so as to prepare negative pole slurry; (D) uniformly spraying the negative pole slurry on a negative pole current collector by using the atomization spray gun, and drying, rolling and cutting pieces to form a negative pole piece; and (E) laminating or winding the prepared positive and negative pole pieces and a polyolefine diaphragm into an electric core, encapsulating the electric core through an aluminium plastic film, injecting an electrolytic solution after vacuum drying, standing to form the lithium ion cell. Compared with the prior art, the preparation method provided by the invention has the advantages that the lithium ion migration journey is shortened, the charge-discharge property is improved, the removing of the dissolvant is easy, the energy consumption of equipment is less, and the technological process is environment-friendly.

Description

technical field [0001] The invention relates to a preparation method of an ultra-low temperature and high rate lithium ion battery. It is especially suitable for a preparation method of a lithium-ion battery that can be discharged at a rate of 5C at a temperature of -40°C. Background technique [0002] Lithium-ion batteries have the characteristics of high nominal voltage, high specific energy, long cycle life, no memory effect, etc., and are environmentally friendly and pollution-free. Therefore, they are widely used in digital products such as mobile phones, notebook computers, and MP3s. At the same time, they are used in electric vehicles , Electric bicycles, national defense equipment and other batteries have also begun to be applied. [0003] In recent years, lithium-ion power batteries have been used more and more widely in various fields. The environment in which batteries are used is complex, and the performance requirements for batteries are higher. Even at lower ...

AI Technical Summary

Problems solved by technology

[0004] The low-temperature battery made by traditional technology can be discharged at a small rate at low temperature, but when it is discharged at a high rate, the battery voltage drops rapidly to the cut-off voltage, and it cannot be discharged at low temperature, which limits the use of lithium-ion batteries in areas with harsh external environments. Applications