Preparation method and applications of high specific capacity sulfur-containing positive electrode material

Abstract

The present invention provides a preparation method and applications of a high specific capacity sulfur-containing positive electrode material. According to the present invention, the phenolic hydroxyl group-rich trapezoidal macromolecule polymer is adopted and reacts with elemental sulfur at a certain temperature, wherein the phenolic hydroxyl group is oxidized into the quinonyl, the sulfur is bonded onto the polymer main chain, and the quinonyl further provides the partial Intercalation / deintercalation lithium capacity, such that the whole specific capacity of the material is effectively increased, and the first discharge specific capacity of the obtained product achieves 1578 mAh / g; the sulfur is firmly bonded onto the polymer main chain through the chemical bond, such that the capacity loss caused by dissolution of the sulfur can be effectively overcome; compared with the method in the prior art, the method of the present invention has characteristics of simple process, easily available raw materials, and mass-production prospects.

Description

technical field [0001] The invention belongs to the field of electrode material preparation, and in particular relates to a preparation method and application of a high specific capacity sulfur-containing cathode material. Background technique [0002] At present, the 3C products of mobile phones and notebook computers are mainly powered by lithium-ion batteries. The theoretical specific energy of lithium-ion batteries is 400-600Wh / kg. Lithium-ion batteries need some necessary auxiliary materials: such as current collectors, diaphragms, electrolytes and packaging. Therefore, the specific energy of lithium-ion batteries actually produced is much lower than the theoretical specific energy, generally between 90 and 200Wh / kg. With the development of high-power consumption products such as smart phones and electric vehicles, it is difficult for existing lithium-ion batteries to fully meet the demanding requirements of these products. [0003] In the past ten years, various new t...

AI Technical Summary

Problems solved by technology

However, the composite positive electrode material formed by porous carbon loaded with sulfur is accompanied by serious volume expansion and contraction during the intercalation and delithiation process, and the intermediate product lithium polysulfide is easily soluble in the electrolyte solution, resulting in the powdering and falling off of the electroactive material on the electrode. and dissolution loss, and the lithium polysulfide dissolved in the electrolyte diffuses to the lithium metal negative electrode and reacts to form lithium sulfide to precipitate on the surface of the negative electrode, resulting in an increase in internal resistance and eventually leading to capacity fading

Images