Battery cathode and preparation method thereof

Abstract

The invention provides a battery cathode. The battery cathode comprises aluminum foil, an electrode layer, an adhesive and a conductive agent; the electrode layer is coated on a surface of the aluminum foil, the electrode layer comprises a matrix layer, a polymer layer cladding the matrix layer, and a core layer located in the matrix layer. Through the battery cathode provided by the invention, aconductive polymer layer coated on the outside of the matrix layer of the electrode layer, the core layer is filled in the matrix layer, a physical limit effect of the one-dimension pipeline and an absorption effect of the chemical component of the matrix layer are utilized at the same time, the problems that the battery specific capacity and cycling retention rate are low and the entire electrochemical performance is low due to the shuttle effect of the intermediate product polysulfur ion generated in the lithium-sulfur battery sulfur cathode charging / discharging process in the prior art canbe solved. The first discharging specific capacity of the battery cathode prepared by adopting the method provided by the invention under the 0.1C multiplying power is 913.4mAh g-1, and the cycling retention rate reaches up to 73.2% after cycling for 100 times.

Description

technical field [0001] The invention belongs to the technical field of battery materials, and in particular relates to a positive electrode of a battery and a preparation method thereof. Background technique [0002] With the rapid development of new energy vehicles and mobile electronic devices, batteries with higher energy density are urgently needed. In the new energy system, lithium-sulfur batteries have become one of the most promising secondary battery systems for the next generation due to their high theoretical specific energy (2600W h / kg), low cost of elemental sulfur, and environmental friendliness. [0003] Typical lithium-sulfur batteries generally use elemental sulfur as the positive electrode and metal lithium sheets as the negative electrode. However, there are three main problems in lithium-sulfur batteries: (1) elemental sulfur and the discharge product lithium sulfide are non-conductive or low-conductive substances, and the conductivity is very poor; (2) t...

AI Technical Summary

Problems solved by technology

However, there are three main problems in lithium-sulfur batteries: (1) elemental sulfur and the discharge product lithium sulfide are non-conductive or low-conductive substances, and the conductivity is very poor; (2) the volume of sulfur will expand and shrink during charging and discharging. , may cause damage to the battery; (3) the shuttle effect of the intermediate product lithium polysulfide, that is, during the charge and discharge process, the polysulfide (Li 2 Sx) intermediate dissolves into the electrolyte, passes through the separator, diffuses to the negative electrode, and directly reacts with the lithium metal of the negative electrode, eventually causing irreversible loss of effective materials in the battery, attenuation of battery life, and low Coulombic efficiency

[0004] However, the existing technology still does not properly solve the problem of the shuttle effect of the intermediate lithium polysulfide

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