A method for preparing a sulfur-based cathode material by using reticulated porous nano-lanthanum oxide

Abstract

The invention relates to a method for preparing the positive electrode of a lithium sulfur battery from an active material, belonging to the field of material chemistry. The method utilizes spray drying technology to prepare porous reticulated nano-lanthanum oxide, and then realizes the composite of porous reticulated nano-lanthanum oxide and sulfur through hydrothermal reaction to obtain rare earth sulfide-based cathode material, and the discharge capacity of the cathode material is as high as 1095mAh / g after being assembled into a battery. The method has high yield and industrial feasibility, and the nano-lanthanum oxide in the obtained rare earth sulfide-based cathode material can guarantee its high conductivity so as to improve the transmission rate of electrons and ions and adsorb soluble polysulfide; The reticulated porous structure can not only provide abundant active sites, but also effectively coat sulfur.

Description

technical field [0001] The invention relates to a method for preparing a positive electrode of a lithium-sulfur battery from an active material, and belongs to the field of material chemistry. Background technique [0002] Rechargeable batteries are undoubtedly one of the most important basic components closely related to human activities, and have been widely used in portable electronic products, such as mobile phones, laptops, cars, wearable sensors and medical equipment, etc., and people are very concerned about their performance Higher and higher demands have been put forward. At present, traditional commercial lithium-ion batteries are limited by their own theoretical specific capacity (300mAh / g) and safety issues, and it is difficult to meet the quality requirements of lithium-ion batteries for practical applications. Therefore, it is of great strategic significance to develop next-generation lithium-ion secondary batteries with high energy density, environmental prot...

AI Technical Summary

Problems solved by technology

First, since elemental sulfur acts as an insulator of electrons and ions at room temperature, the transmission efficiency of electrons and ions is low, which reduces the Coulombic efficiency; second, the reduction intermediate "polysulfide" is dissolved in the electrolyte, resulting in The severe shuttling effect results in a shortened cycle life of Li-S batteries; third, the initial lithiation of sulfur forms long-chain lithium polysulfides (4≤n≤8), which are soluble in organic electrolytes and can pass through the separator to the anode side

Subsequently, it can be further lithiated into low-order short-chain lithium polysulfides (1≤n≤4) deposited on the lithium surface, resulting in continuous fading of capacity and low utilization of active materials.

Fourth, during the charge and discharge process, the sulfur electrode will shrink and expand accordingly, which will destroy the physical structure of the electrode to a certain extent.

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