D.M. Liu, J.X. Ma, S.H. Zheng, W.L. Shao, T.P. Zhang, S.Y. Liu, X. Jian, Z.-S. Wu*, F.Y. Hu*
Energy & Environmental Materials, 2022, e12445.
DOI: 10.1002/eem2.12445 [PDF]
With the rapid development of flexible and portable microelectronics, the extreme demand for miniaturized, mechanically flexible and integrated microsystems is strongly stimulated. Here, biomass-derived carbon (BDC) is prepared by KOH activation using Qamgur precursor, exhibiting three-dimensional hierarchical porous structure. Benefiting from unobstructed three-dimensional hierarchical porous structure, BDC provides an excellent specific capacitance of 433 F/g andprominent cyclability without capacitance degradation after 50000 cycles at 50 A/g.Furthermore,a BDC-based planar micro-supercapacitor (MSC) without metal collector, prepared by mask-assisted coating,exhibits outstanding areal specific capacitance of 84 mF/cm2, and areal energy density of 10.6 μWh/cm2, exceeding most of the previous carbon-based MSCs. Impressively,the MSCs discloses extraordinary flexibility with capacitance retention of almost 100% under extreme bending state. More importantly,a flexible planar integrated system composed of the MSC and temperature sensor is assembled to efficiently monitor the temperature variation,providing a feasible route for flexible MSC-based functional micro-devices.
