Compared with lead-acid, nickel-cadmium, nickel-metal hydride and other batteries, lithium-ion batteries have become one of the hot spots in the current energy field due to their higher energy density, longer service life, smaller volume, and no memory effect. one.

　　Compared with lead-acid, nickel-cadmium, nickel-metal hydride and other batteries, lithium-ion batteries have become one of the hot spots in the current energy field due to their higher energy density, longer service life, smaller volume, and no memory effect. one. The negative electrode material is one of the key components of lithium-ion batteries. It acts as a lithium ion acceptor and realizes the insertion and extraction of lithium ions during the charging and discharging process. Therefore, the quality of the negative electrode material directly affects the overall performance of the lithium-ion battery. At present, graphite and modified graphite are widely used as anode materials for commercial lithium-ion batteries, but their theoretical capacity is only 372mAh/g, which greatly restricts the development of high-energy power batteries. Group IV element (silicon, germanium, tin)-based anode materials have become a research hotspot in the field of anode materials for next-generation lithium-ion batteries due to their higher theoretical capacities (3579mAh/g, 1600mAh/g, 994mAh/g, respectively). However, silicon, germanium, and tin-based negative electrode materials have the problem of large volume expansion during charging and discharging. Long-term charging and discharging will cause pulverization of particles and shedding of active materials, thereby affecting the cycle stability of lithium-ion batteries.

　　In recent years, the advanced lithium-ion battery team led by Han Weiqiang, a researcher at the New Energy Technology Institute under the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, has made a series of progress in high-capacity silicon, germanium, and tin-based anode materials. In terms of high-performance silicon-based anode materials, researchers have developed a low-cost, high-capacity, and high-stability porous silicon-based anode material technology. By coating the porous silicon with carbon, the performance of the silicon-based negative electrode material for lithium-ion batteries is further improved. The silicon-carbon composite electrode material has a capacity retention rate of 86.8% after 300 cycles of charge and discharge. Related research has applied for a Chinese invention patent (201410150747.5, 201410276413.2), and the research results have been published on NanoEnergy (2015, 11, 490-499) in the form of Communication.

　　The 　　 team synthesized and prepared a series of new phase MSn5 (M=Fe,Co,Fe0.5Co0.5) alloy nano-electrode materials based on the previous work using the improved wet chemical method of polyols. The synthesized FeSn5 alloy nanoparticles have a theoretical capacity of 929mAhg-1 when used as a negative electrode material for lithium-ion batteries, which is the material with the highest theoretical specific capacity among the reported M-Sn (M is an electrochemically inert metal) alloy. Researchers have prepared a series of Fe0.5Co0.5Sn5 new phase alloy nanoparticles with a particle size range of 30-50nm, which further expands the Co-Fe-Sn phase diagram. Related achievements have been applied for invention patents (2013104705134, 201310706760X, 2103715406A). At the same time, using in-situ XAFS, in-situ XRD and electrochemical testing methods, the charging and discharging mechanism is discussed and explained in depth. The research on the electrochemical mechanism of this series of tin-based new phase alloy anode materials provides effective theoretical guidance for the team's subsequent development of high-performance tin-based anode materials. Related results were published in JournalofMaterialsChemistryA (2015,3(13):7170-7178) and ACSAppl.Mater.Interfaces (2015,7,7912?7919).