A low-temperature electrode sheet and its preparation method and low-temperature lithium battery

Abstract

The invention relates to a low-temperature electrode sheet, a preparation method thereof, and a low-temperature lithium battery. The low-temperature electrode sheet includes an electrode material and a current collector with a chelate coating on the surface; the current collector with a chelate coating on the surface includes : current collector and the chelate conversion coating on the surface of the current collector; wherein, the chelation conversion coating has P=O and P-OH bonds, and has SiO 2 Nano-layer structure; the chelating conversion coating is passed: vinyl silane is dissolved in a mixed solution of ethanol and acetone to form a first solution, phytic acid is dissolved in a Tris-HCL buffer to form a second solution, and the first solution is added to A chelation reaction occurs in the second solution to obtain.

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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