Low-temperature electrode plate, preparation method thereof and low-temperature lithium battery

Abstract

The invention relates to a low-temperature electrode plate, a preparation method thereof and a low-temperature lithium battery. The low-temperature electrode plate comprises an electrode material anda current collector with a chelating coating on the surface. The current collector with the chelating coating on the surface comprises a current collector and a chelating conversion coating on the surface of the current collector, wherein the chelating conversion coating is provided with a P=O bond and a P-OH bond, and is provided with a SiO2 nano-layer structure; the chelating conversion coatingis obtained by dissolving vinylsilane into a mixed solution of ethanol and acetone to form a first solution, dissolving phytic acid into a Tris-HCL buffer solution to form a second solution, and adding the first solution into the second solution to carry out a chelating reaction.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a low-temperature electrode sheet, a preparation method thereof, and a low-temperature lithium battery. Background technique [0002] Lithium-ion batteries have quickly become one of the most widely used energy storage products due to their high operating voltage, long cycle life, and pollution-free. However, when winter comes, these products are prone to power outages and cannot work, because in low temperature environments, lithium-ion batteries have the characteristics of voltage drop, low discharge capacity, fast capacity decay, and poor rate performance. [0003] The main factors for the poor low temperature performance of lithium-ion batteries are: 1. The viscosity of the battery electrolyte increases at low temperatures and the electrical conductivity decreases; 2. The migration rate of lithium ions in the active material body decreases. This results in incre...

AI Technical Summary

Problems solved by technology

However, the mesh current collector has the following disadvantages in practical applications: on the one hand, the specific surface area is too large, and it is easy to oxidize, resulting in a short warranty period and easy scrapping, and the value of the mesh metal collector is high, which will increase the production cost virtually. , which makes it impossible for lithium battery factories to be practically applied; on the other hand, it is not easy to dry when the slurry is coated on the mesh current collector; The agent is mixed in a solvent to make a slurry, which is then coated on the current collector and dried. If there is no binder, the electrode material is easy to peel off from the current collector, and it is still difficult to improve even if it is changed to a mesh current collector.

However, the binder has almost no conductivity, and it is easy to increase the electrolyte / electrode interface film resistance and charge transfer resistance at low temperatures, thereby reducing the low-temperature performance of the battery.

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