 The paper presents the synthesis of nanoscale cuprous chloride, Cucl, cubic structure using a hydrothermal route, which enhances the electroactive surface areas and leads to high special capacitance of 376mFcm-2 at 1 mAcm-2 with good reversibility and long-term cycling stability, making it a promising candidate as an excellent electrode material. This article was authored by Bo Si-In, Si-Wen Zhang, XIN Zhang, and others.