A highly compressible, nitrogen doped carbon foam based all pseudo-capacitance asymmetric supercapacitors

Compressible supercapacitors are playing an increasingly significant role in sensors and wearable electronic devices. However, compressible supercapacitors have a limited specific capacity as well as lower working voltage. In this work, three-dimensional (3D) N-doped carbon foam is being explored for fabrication of a compressible supercapacitor with pseudocapacitive spinel. The fact that self-growing ZnFe2O4 on highly compressible nitrogen doped carbon foam composite electrodes can deliver significant pseudo-capacitance at negative potentials, an all-pseudocapacitive asymmetric supercapacitor device is fabricated by combining it with NiCo2O4 cathode. The composite electrodes combine the superior electrochemical and mechanical performances with maximum compressive strain of 80% and durability (cyclic strains up to 500 times under the strain of 60%). The asymmetric supercapacitor demonstrates an energy density of 11.84 Wh kg−1 (0.39 mWh cm−3) at 300 W kg−1 (10 mW cm−3), with 96.5% capacitance retention after 15 000 charge-discharge cycles at the compressive strain of 60%. Our work provides new insights for the design of compressible supercapacitors with high performance and accelerates the development of a new generation in energy storage devices with compressibility.