Mesoporous Quaternary Ce-Ni-Mn-Co Oxides as Electrodematerials forHighPerformance Flexible Solid-StateAsymmetric Supercapacitors

Mesoporous quaternary Ce-Ni-Mn-Co oxides microspheres have been successfully prepared by a solvothermal approach and subsequent heat treatment in air. As-prepared mesoporous quaternary Ce-Ni-Mn-Co oxides microspheres show a large specific surface areas of 146.1 m(2) g(- 1). When evaluated as an electrode of supercapacitors, the Ce-Ni-Mn-Co oxides microspheres presents an outstanding specific capacitance of 1840.6 F g(- 1) at 1.0 A g(- 1). Furthermore, a flexible solid-state asymmetric supercapacitor based on Ce-Ni-Mn-Co oxides was also as- sembled, which possessed a highenergy density of 0.43 mW h cm(- 3) and good electrochemical stability for 5000 cycles chargedischarge measurement. Encouragingly, the flexible solid-state electrochemical energy storage device shows well mechanical flexibility under various bending angles. The excellent electrochemical performances indicate the mesoporous quaternary Ce-Ni-Mn-Co oxides microspheres are promising electrode materials in the energy storage.