Lithium-sulfur battery positive electrode and preparation method thereof

Abstract

The invention discloses a lithium-sulfur battery positive electrode and a preparation method thereof. The preparation method comprises the steps of uniformly mixing a positive active substance, a conducting agent and a bonding agent to obtain a mixture, smearing the mixture on a current collector as an active substance layer, and drying the current collector to obtain a positive substrate; uniformly mixing a conducting agent, a bonding agent and a dispersing agent to obtain a conducting sizing agent, smearing the conducting sizing agent on the outer surface of the positive substrate as a protective layer, and drying the positive substrate to obtain the lithium-sulfur battery positive electrode. The preparation method is simple and easy to operate, easy to control and suitable for industrialized production; in the prepared lithium-sulfur battery positive electrode, the protective layer plays a role of a conducting, sulfur intercepting and electrode stabilizing structure, so that the capacity, multiplying power and cycling stability of a lithium-sulfur battery can be effectively improved, the thickness of the protective layer is easy to control, and the influence on the sulfur content of the positive electrode can be reduced as far as possible.

Description

technical field [0001] The invention relates to the technical field of lithium-sulfur batteries, in particular to a lithium-sulfur battery positive electrode and a preparation method thereof. Background technique [0002] With the growth of population and economy and the improvement of people's living standards, the demand for energy is increasing year by year, and the environmental pollution caused by the use of fossil energy is also becoming more and more serious. In order to reduce dependence on fossil energy, new energy technologies based on renewable energy are rapidly developed and applied. Lithium-sulfur battery is an inexpensive rechargeable battery with high energy density (the theoretical energy density of lithium-sulfur battery is as high as 2600W h kg -1 ), considered to be one of the most attractive battery systems in the future. However, lithium-sulfur battery technology also faces many problems from materials and systems: First, the resistivity of active mat...

AI Technical Summary

Problems solved by technology

However, lithium-sulfur battery technology also faces many problems from materials and systems: First, the resistivity of active material sulfur is relatively high (5×10 -30 S cm -1 , 25°C); secondly, sulfur will expand in volume during the charge-discharge cycle, leading to the destruction of the sulfur electrode structure; thirdly, the polysulfides formed during the cycle are easy to dissolve in the electrolyte, and the electrode active materials gradually decrease. Lower specific capacity

Other methods improve the utilization of active materials by designing new battery configurations, for example, Arumugam Manthiram et al [Su Y S, Manthiram A. Lithium–sulfur batteries with a microporous carbon paper as a bifunctional interlayer. [J] Nature Communications, 2012, 3: 1166.] A porous conductive interlayer is added between the pole piece and the separator to prevent the shuttle of polysulfide compounds and achieve the purpose of improving the electrochemical performance of lithium-sulfur batteries. However, the addition of

Images