Simple Designed Micro-Nano Si-Graphite Hybrids for Lithium Storage

Up to now, the silicon-graphite anode materials with commercial prospect for lithium batteries (LIBs) still face three dilemmas of the huge volume effect, the poor interface compatibility, and the high resistance. To address the above challenges, micro-nano structured composites of graphite coating by ZnO-incorporated and carbon-coated silicon (marked as Gr@ZnO-Si-C) are reasonably synthesized via an efficient and convenient method of liquid phase self-assembly synthesis combined with annealing treatment. The designed composites of Gr@ZnO-Si-C deliver excellent lithium battery performance with good rate performance and stable long-cycling life of 1000 cycles with reversible capacities of 1150 and 780 mAh g(-1) tested at 600 and 1200 mA g(-1), respectively. The obtained results reveal that the incorporated ZnO effectively improve the interface compatibility between electrolyte and active materials, and boost the formation of compact and stable surface solid electrolyte interphase layer for electrodes. Furthermore, the pyrolytic carbon layer formed from polyacrylamide can directly improve electrical conductivity, decrease polarization, and thus promote their electrochemical performance. Finally, based on the scalable preparation of Gr@ZnO-Si-C composites, the pouch full cells of Gr@ZnO-Si-C parallel to NCM523 are assembled and used to evaluate the commercial prospects of Si-graphite composites, offering highly useful information for researchers working in the battery industry.

Automated summary

By synthesizing micro-nano structured composites of Gr@ZnO-Si-C, the three dilemmas faced by silicon-graphite anode materials have been successfully addressed, leading to excellent lithium battery performance. The incorporated ZnO improves interface compatibility, while the pyrolytic carbon layer enhances electrical conductivity, ultimately boosting electrode performance.