【Achievements Introduction】

　　Professor Zhu Jia's research group from the School of Modern Engineering and Applied Science of Nanjing University was invited to publish a progress report "Challenges and recent progress in the development of Sianodes for lithium-ion battery" (DOI: 10.1002/aenm.201700715) on Advanced Energy Materials, summarizing the silicon anode of lithium-ion batteries that has attracted much attention in recent years. and outlook.

　　【research content】

　　Figure 1 Overview of silicon-based anodes for lithium-ion batteries

　　a-c) Basic challenges

　　d-f) Commercialization-oriented challenges and recent progress

　　Figure 2 Solutions to basic silicon anode problems

　　a) Schematic diagram of silicon nanowires

　　b) Size-dependent fracture of silicon nanoparticles

　　【research content】

　　With the rapid development of electronic portable devices and electric vehicles, research and development of high-performance lithium-ion batteries is particularly critical. Silicon anode for lithium-ion batteries is considered to be one of the most ideal anode materials for the next generation. Due to its huge reserves and ultra-high theoretical specific capacity (4200mAh/g, which is equivalent to ten times the current commercial graphite anode), it has become a technology It is one of the focuses of attention from the world and industry.

　　This progress report first introduces the basic problems and solutions of silicon anodes, and then focuses on summarizing the problems that still need to be solved for commercialization of silicon anodes and the progress in recent years, mainly including the first-cycle Coulombic efficiency, tap density and material cost. aspects, and finally an outlook on future work in terms of full battery performance and energy density is given. The nanostructured silicon anode solves the problems of material crushing and unstable SEI caused by volume expansion when silicon is embedded with lithium, and improves electrochemical cycle performance. However, the high specific surface area of the nanostructure results in low first-cycle Coulombic efficiency, low tap density and area specific capacity. At the same time, the preparation process of the nanostructure is complex and the cost is high. These factors have seriously affected the commercialization of silicon anodes. This article summarizes the progress in first-cycle Coulombic efficiency from three aspects: secondary structure design, pre-embedded lithium and electrolyte additives. It also summarizes the improvement of tap density and area specific capacity from the aspects of micron structure design and conductive binder. Reduce material costs from low-purity silicon and natural silicon sources. Finally, future work is prospected in terms of full battery performance and energy density.

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