Composite positive electrode sheet lithium ion battery with high energy density

Abstract

The invention discloses a composite positive electrode sheet lithium ion battery with high energy density. A positive electrode sheet is a composite positive electrode sheet. The composite positive electrode sheet is of a multilayer composite structure. The positive electrode sheet includes a positive electrode current collector. The negative side of the positive electrode current collector is coated with a first positive electrode material layer. The positive side of the positive electrode current collector is coated with a second positive electrode material layer. The surface of the first positive electrode material layer is coated with a third positive electrode material layer. The surface of the second positive electrode material layer is coated with a fourth positive electrode material layer. A polydopamine material layer is sprayed between the first positive electrode material layer and the third positive electrode material layer. A polydopamine material layer is sprayed betweenthe second positive electrode material layer and the fourth positive electrode material layer. The lithium ion battery of the invention has the characteristics of high compaction density, excellent electrochemical performance, convenient processing, good quality stability and low cost.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a lithium-ion battery with a high energy density composite positive plate. Background technique [0002] Lithium-ion battery is a secondary battery (rechargeable battery), which mainly relies on lithium ions to move between the positive and negative electrodes to work. During the charging and discharging process, Li+ intercalates and deintercalates back and forth between the two electrodes: when charging, Li+ is deintercalated from the positive electrode, intercalated into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; the opposite is true during discharge. [0003] In the electrode, the compaction density of the pole piece is related to the softness, hardness and pressure of the material. Generally speaking, the coating of the pole piece requires a gap of tens of nanometers to facilitate the wetting and entry ...

AI Technical Summary

Problems solved by technology

[0007] It can be seen that the high energy density of the invention is improved by increasing the compaction density one-sidedly, which causes the active material particles in the pole piece to be too dense, and the electrolyte penetration is difficult, which restricts the performance of the battery rate charge and discharge performance; at the same time, the pole piece Another hidden danger brought by high compaction density is the high brittleness of the pole piece, which is easy to break off in the process of processing and winding, and needs to be repaired, which also forms a huge waste of materials.