Progress in research on anode materials for lithium-ion batteries

The research group of Professor Lu Anhui of Dalian University of Technology has recently innovatively proposed that the solvent-free method uses nano binary metal oxide (znsno3) as the precursor to grow metal organic framework zif-8 in situ to prepare sn@c composites. . According to the theory of soft and hard acid and base, 2-methylimidazole as a junction base preferentially combines with the junction acid zn2+ to form zif-8. The subsequent pyrolysis process converts zif-8 into a nitrogen-containing conductive carbon network, and znsno3 is carbon thermally reduced to nanometers. Tin particles and elemental zinc, elemental zinc dynamically volatilizes at high temperature due to its low melting point to create abundant pores, which is beneficial to the transmission of ions and electrons.

Preparation of electrode materials for lithium-ion batteries with both high energy density and high power density is a research hotspot in recent years. Because of its high specific capacity, tin-based materials are considered to be very potential materials that can replace traditional graphite anodes. However, the severe volume expansion during charging and discharging leads to electrode powdering and particle agglomeration, which leads to rapid capacity decay and low conductivity. The development of effective electrode material preparation methods and improving the conductivity of composite electrode materials are the key to improving the electrochemical performance of tin anodes.

The new synthesis method ensures the high dispersion of tin nanoparticles in the composite material. The developed pore structure and high nitrogen content can effectively alleviate the volume expansion during the lithium insertion process. Improve conductivity. The battery performance test results show that the first discharge capacity of the prepared sn@c composite is 1321mahg-1, and the first coulombic efficiency is as high as 80.1%. The capacity remained at 901mahg-1 after 150 cycles. In addition, this synthesis method can be extended to the preparation of other materials and also exhibit excellent electrochemical performance.