Although lithium-ion batteries have been used in all aspects of people’s lives, scientists have always believed that sodium-ion batteries are more efficient than lithium-ion batteries in terms of large-scale energy storage. It is safe and cheaper, but due to its short life, it cannot be applied in the short term. Recently, Chinese and American scientists jointly developed a new structure of antimony sulfide-based negative electrode material, which has increased the cycle life of antimony sulfide-based sodium-ion batteries from no more than 500 cycles to 900 cycles. Its lifespan is almost comparable to that of lithium batteries, and its specific capacity It is 1.5 times the capacity of the negative electrode material (graphite) of lithium-ion batteries. Relevant results were published in ACS Nano, the top magazine in the nanometer field.
Xiong Xunhui, the first author of the paper and associate professor at the School of Environment and Energy of South China University of Technology, said in an interview with a reporter from Science and Technology Daily that the working principle of sodium-ion batteries is similar to that of lithium-ion batteries, both of which use ions between the positive and negative electrodes. The embedding and disengagement process realizes charging and discharging. However, the former has lower costs due to its abundant sodium resources, and is safer due to its high voltage platform. However, due to the unsatisfactory performance of existing sodium-ion electrode materials, finding suitable electrode materials has been the key to the development of sodium-ion batteries from the 1980s to the present.
Xiong Xunhui and Liu Meilin, a professor at the School of Materials Science and Engineering at the Georgia Institute of Technology, developed a simple method, which is to mix commercial antimony sulfide and graphene oxide in a sodium sulfide solution, and then control crystallization and sintering. Preparation of composite materials of modified graphene and nano-antimony sulfide. When the material and sodium flakes are assembled into a half-battery, the capacity retention rate is still as high as 83% after 900 cycles of rapid charge and discharge (charge and discharge are completed in about 40 minutes).
Researchers have proved through theoretical calculations that modified graphene has a better fixation effect on antimony sulfide and its discharge products, and can more effectively stabilize the structure of the material and prevent active materials from falling off the graphene. . Compared with existing reports, this composite material has the best cycle performance of antimony-based anode materials for sodium-ion batteries, bringing a big step closer to the application of sodium-ion batteries.
