Nano-CaCO3 templated porous carbon enable high-rate and ultralong cycle performance supercapacitor

Abstract

The development of hierarchically porous carbon materials with excellent pore structure via environmentally friendly and low-cost strategies is attractive for high energy density of supercapacitor. Zinc gluconate is an excellent precursor of carbon materials due to its low cost, simple chemical composition, and self-activation during carbonization. In this work, a strategy of activating zinc gluconate with nano‑calcium carbonate as template was proposed to prepare porous carbon (ZnPCCa-1), which has the advantages of high specific surface area of 1328 m2 g−1. The as-prepared ZnPCCa-1 electrode achieved ultra-high rate performance of specific capacitance ∼120 F g−1 at the current density of 20 A g−1, and capacitance retention with 95.1 % even at high current density of 50 A g−1 after 50,000 cycles. The symmetric supercapacitor prepared by ZnPCCa-1 electrode assembly achieves an energy density of 81.1 Wh kg−1 in Et4NBF4 electrolyte, and the capacitance retention keep up to 89.7 % after 10,000 cycles at current density of 20 A g−1. This work demonstrates a promising approach for intelligently regulating hierarchical porous structured carbon, and providing valuable insights for achieving high-performance supercapacitor storage.