Lotus Leaf-Derived Hierarchically Porous Hard Carbon Nanosheets as Anode for Highly Robust Potassium-Ion Batteries

Owing to abundant resources, low redox potential, and low expense, potassium-ion batteries (PIBs) have received continuous attention as a rookie of renewable electricity storage equipment. To obtain high-performance PIBs based energy storage, the energy storage anode must provide a stable and suitable structure for large-sized active potassium ions. To this end, a lotus leaf-derived, hierarchically porous activated carbon (LHPAC) was mainly obtained by a bionic strategy. The prepared LHPAC with a hierarchically porous structure not only affords fast transportation for both electrons and potassium ions but also supplies the necessary void space to avoid structural instability incurred by volume dilatation in the process of electrode operation. Therefore, the LHPAC exhibited exceptional reversible capacity (170 mA . h . g(-1) at 50 mA . g(-1)) and superb cycle solidity (0.016% tiny capacity attenuation per cycle at 200 mA . g(-1), capacity retention rate of 86.3% after 870 cycles), as well as inimitable rate performance. This work demonstrates the great application prospects of biomass-derived carbon materials as, anode for sturdy PIBs.