“…Even when the energy density was 27.22 W h kg −1 , the power density was as high as 10 kW kg −1 . When compared with other reported biochar capacitors such as AC-700//AC-700 (19.9 W h kg −1 , 700 W kg −1 ), 58 MnO 2 /NBC/PEDOT (7.8 W h kg −1 , 706.3 W kg −1 ), 59 WBMs-800//WBMs-800 (9.4 W h kg −1 , 227 W kg −1 ), 60 TBC-K 3.6 //TBC-K 3.6 (6.7 W h kg −1 , 110 W kg −1 ), 61 HBFC-1//HBFC-1 (13.1 W h kg −1 , 225 W kg −1 ), 62 and NFAC-c//NFAC-c (22 W h kg −1 , 80 W kg −1 ) 63 our results were superior. Meanwhile, our results were closed to other reported capacitors based on modified biochar, including FBC//FCBC (45.1 W h kg −1 , 900 W kg −1 ), 64 FBC//MBC (30.8 W h kg −1 , 900 W kg −1 ), 64 BMIMBF 4 /AN (46.38 W h kg −1 , 300 W kg −1 ), 65 and Ni(OH) 2 -MnO 2 -RGO//NBKBC (39.5 W h kg −1 , 264 W kg −1 ) 66 (Table S5†).…”