The hierarchical porous N/O co-functionalized carbon(HPNOC)was scalably prepared by using the lowcost and renewable blighted grains as the raw material coupled with mild KHCO_3 activation for electrochemical capacitor...The hierarchical porous N/O co-functionalized carbon(HPNOC)was scalably prepared by using the lowcost and renewable blighted grains as the raw material coupled with mild KHCO_3 activation for electrochemical capacitors(ECs).The elemental N was in situ doped in the obtained HPNOC without any N-containing additives.Remarkably,the obtained HPNOC was endowed with a large specific surface area(about 2 624m^2·g^(-1)),high pore volume(about 1.35cm^3·g^(-1)),as well as high-content N/O functionalization(about 1.9%(in atom)N and about 10.2%(in atom)O.Furthermore,the as-resulted HPNOC electrode with a high mass loading of 5mg·cm^(-2 )exhibited competitive gravimetric capacitances of about 373.6F·g^(-1 )at 0.5A·g^(-1),and even about 260.4F·g^(-1 )at a high rate of 10A·g^(-1);superior capacitance retention of about 98.8%at 1A·g^(-1 )over 10 000consecutive cycles;and high specific energy of about 9.6W·h·kg^(-1 )at a power of 500W·kg^(-1),when evaluated as a promising electrode in 6mol KOH for advanced electrochemical supercapacitors.More encouragingly,the green synthetic strategy we developed holds a huge promise in generalizing for other biomass-derived carbon materials for versatile energy-related applications.展开更多
基金supported by the National Natural Science Foundations of China(Nos.51572005,51772127)
文摘The hierarchical porous N/O co-functionalized carbon(HPNOC)was scalably prepared by using the lowcost and renewable blighted grains as the raw material coupled with mild KHCO_3 activation for electrochemical capacitors(ECs).The elemental N was in situ doped in the obtained HPNOC without any N-containing additives.Remarkably,the obtained HPNOC was endowed with a large specific surface area(about 2 624m^2·g^(-1)),high pore volume(about 1.35cm^3·g^(-1)),as well as high-content N/O functionalization(about 1.9%(in atom)N and about 10.2%(in atom)O.Furthermore,the as-resulted HPNOC electrode with a high mass loading of 5mg·cm^(-2 )exhibited competitive gravimetric capacitances of about 373.6F·g^(-1 )at 0.5A·g^(-1),and even about 260.4F·g^(-1 )at a high rate of 10A·g^(-1);superior capacitance retention of about 98.8%at 1A·g^(-1 )over 10 000consecutive cycles;and high specific energy of about 9.6W·h·kg^(-1 )at a power of 500W·kg^(-1),when evaluated as a promising electrode in 6mol KOH for advanced electrochemical supercapacitors.More encouragingly,the green synthetic strategy we developed holds a huge promise in generalizing for other biomass-derived carbon materials for versatile energy-related applications.
