Important effect of Pt modification at the collector/active material interface of flexible micro-supercapacitors

The interface modification of collector/active materials is important for enhancing the performance of micro-supercapacitors (MSCs). In this study, we report that the performance of MnO2 based MSCs is greatly improved only by adding a small amount of Pt modification on Au current collector. The MSCs were fabricated in the interdigitated planar form on polyethylene terephthalate (PET) substrate. LiCl-polyvinyl alcohol (PVA) was used as solid electrolyte to make these all-solid-state flexible MSCs. The area specific capacitance of Pt modified MnO2/Pt@Au/PET MSCs are more than two times higher than those of MnO2/Au/PET MSCs without Pt modification. MnO2/Pt@Au MSCs has relatively higher energy density ranges from 0.36 to 0.88 μWh cm−2 and power density ranges from 0.04 to 0.16 mW cm−2. In addition, the MnO2/Pt@Au/PET MSCs showed excellent long-term cycling stability with nearly no performance attenuation after 5000 times of galvanostatic charge/discharge cycles. Our results indicate that the interface modification of collector/active materials should receive sufficient attention to optimize and improve the storage performance and stability for MSCs.