有可能是电极制作工艺没控制好，我用过硫酸、KOH和有机电解液都近似矩形，可以参考：
Title: A general approach for fabrication of nitrogen-doped graphene sheets and its application in supercapacitors
Author(s): Wang, Dewei; Min, Yonggang; Yu, Youhai; et al.
Source: Journal of Colloid and Interface Science Volume: 417 Issue: 0 Pages: 270-277 Published: 2014
Times Cited: 23
Title: Facile synthesis of wheat bran-derived honeycomb-like hierarchical carbon for advanced symmetric supercapacitor applications
Author(s): Wang, Dewei; Min, Yonggang; Yu, Youhai
Source: Journal of Solid State Electrochemistry Volume: 19 Issue: 2 Pages: 577-584 Published: 2015/02/01
Title: Laser induced self-propagating reduction and exfoliation of graphite oxide as an electrode material for supercapacitors
Author(s): Wang, Dewei; Min, Yonggang; Yu, Youhai; et al.
Source: Electrochimica Acta Volume: 141 Issue: 0 Pages: 271-278 Published: 2014
Title: A melt route for the synthesis of activated carbon derived from carton box for high performance symmetric supercapacitor applications
Author(s): Wang, Dewei; Fang, Guoli; Xue, Tong; et al.
Source: Journal of Power Sources Volume: 307 Pages: 401-409 Published: MAR 1 2016 ，
