锂离子电池用多孔硅基负极的研究进展OA

Silicon(Si)is considered as a potential next-generation negative electrode material due to its high theoretical specific capaci-ty(4200 mAh/g),low operating voltage platform[0.2～0.3 V(vs.Li/Li+)],and abundant reserves.However,there are still two key issues to be solved in the practical application:First,Si is a semiconductor material which possesses poor electronic conductivity;Secondly,there is a huge volume change in the Si anode during the process of lithiation/delithiation process,which leads to the falling off of active materials and even pulverizing.Further,huge volume change can lead to the repeated formation of solid electrolyte(SEI)film and the increase of interface resistance,which have negative effects on capacities and cycle stabilities.Porous Si structure can provide more space for buffering the volume change and providing efficient electrons/ions transportation channels.Meanwhile,the high specific sur-face area also facilitates full contact between the electrode and the electrolyte,providing more reaction sites.Herein,based on the fail-ure mechanism of silicon anode,the effects of porous microstructure,surface coating,silicon alloying,and free-standing structures on the performance of lithium storage were reviewed,and the capacity attenuation mechanism of different porous silicon modification was analyzed.Consequently,the challenges and development prospects of porous silicon-based negative electrode in the next generation of lithium-ion batteries were discussed.