A mushroom derived biomass carbon as high-stability anode for potassium ion battery

As an alternative to Li-ion batteries, potassium-ion batteries have attracted increasing research interest due to the natural abundance of potassium and low cost. However, the larger ionic radius of the potassium easily causes a large volume expansion of the anode materials, eventually hindering the practical application of potassium-ion batteries. Here, we reported a heteroatomic doping mushroom biomass carbon (HDMC) as anode material for potassium-ion batteries. With high surface area and rich heteroatomic doping (N, S, and P), the as-prepared porous HDMC not only provides sufficient void space to relieve volume expansion of electrode but also offers highly efficient channels for fast transport of both electrons and potassium ions. The results demonstrated that the HDMC showed relatively high specific capacity (290 mAh g−1 at 500 mA g−1) and outstanding cycling stability after 2000 cycles. In-situ Raman spectroscopy and galvanostatic intermittent titration confirmed its surface-dominated potassium storage behavior with fast de-/potassiation kinetics, satisfactory reversibility, and fast ion/electron transport. This work guides an effective bionic strategy for the preparation of biomass carbon as high-performance anode materials.