Structure optimization and electrolyte regulation boost K-storage performance of graphite anode

Modified graphite (MG) with rough edges and reduced crystal particles is developed via ball-milling treatment for commercializable K-storage anode. Importantly, rational electrolyte regulation significantly improves the reaction dynamics as well as reversibility of potassiation/depotassiation behaviors, resulting into a high and stable reversible capacity of 277 mA h g−1 at 200 mA g−1 after 250 cycles in the optimized 3 M KFSI/EC + DEC electrolyte. The enhanced K+-solvents interaction with aggregates (AGGs)-rich solvated structures is revealed to be responsible for the excellent K-storage performance. Furthermore, electrolyte flammability evaluation confirms the remarkably suppressed flammability of the optimized 3 M KFSI/EC + DEC, providing enough security for practical applications of PIBs. [Display omitted] •A commercial-based modified graphite has been simply developed.•A reversible capacity of 300 mAh g−1 with 0.017% per cycle decline is achieved.•Improved reaction kinetics by electrolyte regulation was responsible for K-storage.•The non-inflammability of the optimized electrolyte was enhanced.