Heterostructured MoO3@CoWO4 nanobelts towards high electrochemical performances via oxygen vacancies generation

Heterostructured nanomaterials tend to have a high proportion of oxygen vacancies (V O ) due to the presence of heterogeneous interfaces. Herein, a new kind of heterostructured MoO 3 @CoWO 4 nanobelts was successfully evaluated as fascinating cathode material . SEM and TEM analysis indicated that the MoO 3 nanobelts were fully blanketed with CoWO 4 nanodots . The generation of Vo species was confirmed by XPS and EPR data. By profiting both synergistic and Vo generation effects, MoO 3 @CoWO 4 electrode displayed an excellent capacitance of 246 mAh·g −1 (1966 F·g -1 at 0.5 A·g −1 ) with high-rate capability of 174 mAh·g −1 (1394 F·g −1 at 30 A·g −1 ) as well as superb stability of 94 % (over 15,000 cycles). Notably, all-solid-state device delivered a good energy value of 63.1 Wh·kg −1 at 375 W·kg −1 . Interestingly, the supercapacitor device showed super-low self-discharge comportment of only 12.1 % during 24 h. Importantly, the generation of the V O defects could control the ions diffusion process and lead a sharp decrease in the self-discharge process.