P/N/O co-doped carbonaceous material based supercapacitor with voltage up to 1.9 V in aqueous electrolyte

Phosphorus, nitrogen and oxygen co-doped carbonaceous materials (PNODC) were facilely prepared by pyrolyzing phosphorus, nitrogen and oxygen-rich phytic acid doped polyanilines. ICP analysis and elemental analysis demonstrate that the maximum phosphorus content of the as-prepared PNODC reaches 6.02 wt% with the total heteroatom (phosphorus, nitrogen and oxygen) content up to 32.76 wt%. The symmetric supercapacitor built from PNODC could be operated at a very high working voltage of 1.9 V. A maximum energy density of 21.8 W h kg(-1) is achieved at a power density of 238 W kg(-1) and a voltage load of 1.9 V. The excellent electrochemical performance can be attributed to the high heteroatom content, the synergetic effect of phosphorus and nitrogen/oxygen co-doping and the protection of abundant heteroatom functionalities on the surface of the carbon electrodes.