Untra‐high pseudocapacitance enhanced anode of N, P dual‐doped carbon nanosheet derived from biomass toward high performance sodium ion battery

Abstract

In order to improve the cycling capability and rate performance of carbon anode material for sodium ion battery, an easy, green, and scalable thermal pyrolysis method is exploited to synthesize the nitrogen, phosphorus dual‐doped carbon nanosheets from abundant biomass of peach kernel shell and diammonium hydrogen phosphate. This biomass carbon material demonstrates a super‐thin nanosheet microstructure, and its surface area reaches about 2262 m 2 g –1 . This carbon nanosheet electrode exhibits a large initial coulombic efficiency of 90%, superior rate capability, and high sodium ion storage capacity. It delivers a high Na + storage capacity of about 332 mAh g –1 at a current density of 100 mA g –1 after 200 cycles. Even at a high current density of 4 A g –1 , a good rate performance of 270 mAh g –1 is also achieved. The ultra‐high pseudocapacitance contribution over 90% is the major reason for the excellent Na + storage performance of this carbon nanosheet electrode. This nitrogen, phosphorus doped biomass carbon anode material with an excellent storage capacity of sodium ion, makes it an appealing candidate for cheap and high‐performance anode materials for sodium ion batteries.