A coating slurry and coating and lithium ion battery and use thereof

Abstract

The present disclosure provides a coating slurry comprising a binder, a structural medium, a pore former, and a solvent. The present disclosure also provides a coating obtained by curing the coating slurry as described above. The present disclosure also provides a lithium ion battery, the lithium ion battery includes an anode electrode sheet, a cathode electrode sheet and a separator; the capacity of the anode electrode sheet per unit area is the same as the capacity of the cathode electrode sheet per unit area. The ratio of the capacity is (0.01-1):1; the surface of the anode electrode sheet has a coating, the coating contains a structural medium and a cured binder, and the coating has holes. The present disclosure also provides a use of the above-mentioned coating slurry, the above-mentioned coating layer or the above-mentioned lithium ion battery in manufacturing an electric vehicle. The present disclosure can effectively improve the energy density of the power battery, while ensuring that its long-term reliability and safety performance are not affected.

Description

technical field [0001] The present disclosure relates to the field of lithium batteries, in particular, to a coating slurry, a coating, a lithium ion battery and their uses. Background technique [0002] With the development of electric vehicles, the requirements for the energy density of power batteries (the current normal level of 180-230wh / kg) are getting higher and higher. As the core component of electric vehicles, the energy density of power batteries affects the design of the whole vehicle, including the performance of the whole vehicle. and cost control, high-energy-density power batteries can effectively control the weight of the vehicle and the design of other components. In addition, power batteries account for nearly 50% of the cost of electric vehicles. Increasing the energy density of power batteries will reduce the cost of non-energy units such as mechanical parts. cost, so as to effectively control the cost of the whole vehicle. [0003] In the prior art: th...

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Problems solved by technology

[0003] In the existing technology: the battery cathode increases the capacity per unit weight of the cathode by increasing the Ni content in the cathode material. The increase in the Ni content reduces the oxygen evolution potential of the cathode, which brings the risk of high gas production in the battery cell, which will deteriorate the battery cell. Long-term reliability, the increase in the upper limit of the cathode voltage increases the oxidation of the cathode at the charging end, which will accelerate the oxidation of the electrolyte and diaphragm, thereby deteriorating gas production and adversely affecting long-term reliability

[0004] Anode by adding Si / SiO 2 Alloys are used to improve the capacity per unit weight of the anode. During the charging and discharging process, there is a very large shrinkage and expansion. Under a higher shrinkage-expansion ratio, there will be a phenomenon of peeling off the film and powder, and at the same time affect the stability and integrity of the SEI film on the surface of the anode. Deteriorates long-term cell life and capacity retention

[0005] At the same time, the increase in the coating weight of the anode will deteriorate the power, charging window and long-term cycle life of the battery, which will also bring great challenges to the process and equipment; the reduction of the base material mainly affects the process manufacturing, and the thin base material is easy to break during the battery manufacturing process , which seriously affects the process efficiency of the battery cell, thereby increasing the cost; as a component that isolates the cathode and anode from direct contact with the short circuit, its thickness is very important for the control of the safety of the short circuit in the battery cell, and reducing the thickness will bring the safety risk of the short circuit in the battery cell

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