Amidation structure design of carbon materials enables high energy and power density symmetric Sodium-ion battery.

• Carbon material amidation is presented for sodium-ion battery electrodes. • Amide group renders anode enlarged interlayer distances and active sites. • Symmetric sodium-ion battery has high energy and power density. • The strategy features low cost, scale production, and environmental friendliness. Structure design of carbon materials, like the heteroatom doping, is one of the effective strategies to develop high-performance anode of sodium-ion battery (SIB). However, challenges remain in sodium ion storage capacity, rate capability and cycle life. Here, an amidation structure design strategy is rationally proposed, and the regulated electrode exhibits not only remarkable electrochemical performance, but also great potential in scale commercial production. Mesocarbon microbead (MCMB), a graphitic spherical particle with excellent physiochemical properties but low-cost production process, is applied to the amidation process, achieving enlarged interlayer distances up to ∼ 0.42 nm and rich –CONH 2 active sites. The amidated MCMB (MCMBO-NH 2) anode displays a high specific capacity of 220 mAh/g, with a retention rate of about 83.6 % after 500 cycles. The MCMBO-NH 2 cathode remains stable at the specific capacity of 141 mAh/g after 250 cycles. The symmetric sodium-ion full cell then demonstrates a high energy density of 145 Wh/kg at a large power density of 12,500 W/kg, and an excellent capacity retention rate of 96.1% after 500 cycles, which is superior to the previous work of the symmetric SIBs. The amidation design of carbon materials comes with outstanding battery performance and cost-effective production process, offering a significant commercial value for the industrialization of SIBs. [ABSTRACT FROM AUTHOR]