Lithium ion battery and electronic device

Abstract

The invention provides a lithium ion battery and an electronic device. The lithium ion battery comprises a positive plate, a negative plate, a diaphragm and an electrolyte; the diaphragm comprises a base membrane and a ceramic layer arranged on at least one functional surface of the base membrane, and the ceramic layer comprises inorganic particles m and inorganic particles n; the volume average particle size of the inorganic particles m is 0.5-1.5 [mu]m, and the volume average particle size of the inorganic particles n is 0.05-0.3 [mu]m; the mass ratio of the inorganic particles n to the inorganic particles m is A, and A is more than or equal to 0.05 and less than or equal to 10; the electrolyte comprises ethylene carbonate, the mass ratio of the ethylene carbonate to the electrolyte is B, and B is more than or equal to 0.05 and less than or equal to 0.4; and A and B satisfy 1 <= A / B <= 100. According to the lithium ion battery disclosed by the invention, the lithium ion battery has excellent cycle performance and safety performance on the basis of high energy density.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and relates to a lithium ion battery and an electronic device. Background technique [0002] In recent years, the development of high-energy-density lithium-ion batteries has always been an important research direction in the field of lithium-ion battery technology. Improving the energy density of lithium-ion batteries can significantly improve the performance of end products. For example, higher energy density of lithium-ion batteries can Make smart electronic products have higher battery life. [0003] At present, the main means to improve the energy density of lithium-ion batteries include increasing the effective compaction density of the electrode and using thinner materials, etc., but these methods have the following technical defects: 1) The compaction density is inversely proportional to the porosity of the electrode, and the compaction density The larger the size, the grea...

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Problems solved by technology

[0003] At present, the main means to improve the energy density of lithium-ion batteries include increasing the effective compaction density of the electrode and using thinner materials, etc., but these methods have the following technical defects: 1) The compaction density is inversely proportional to the porosity of the electrode, and the compaction density The larger the size, the greater the degree of extrusion between the material particles, the smaller the porosity of the pole piece, the worse the electrolyte absorption performance of the pole piece, the harder it is for the electrolyte to infiltrate, and the poorer the liquid retention capacity of the battery. During the battery cycle, the polarization will be large, and the battery capacity will decay greatly, which will lead to poor cycle performance of the battery; 2) The use of thinner materials will reduce the passing rate of the battery in safety tests, which is also an important factor for battery safety performance. big challenge

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