A novel CuCo2S4/polyacrylonitrile ink for flexible film supercapacitors

[Display omitted] •The CuCo2S4/polyacrylonitrile ink revealed an excellent film forming property and superior heat stability.•Massive CuCo2S4 nanosheets were embedded in the polyacrylonitrile film tightly.•The CuCo2S4/polyacrylonitrile film electrode exhibited a high specific capacitance and great cycling stability. This is the first investigation of the CuCo2S4/polyacrylonitrile ink for flexible film supercapacitors, which contains CuCo2S4 nanosheets and modified polyacrylonitrile molecular chain. Significantly, this novel ink revealed an excellent film forming property and superior heat stability. As a product, the CuCo2S4/polyacrylonitrile film electrode exhibited a high specific capacitance (385 F g−1 at 1 A g−1) and great cycling stability (92.1% retention at 10 A g−1 for 2000 cycles) for practical energy storage applications.