Bio-derived hierarchically porous heteroatoms doped‑carbon as anode for high performance potassium-ion batteries.

K-ion batteries (KIBs) are widely considered as a promising alternative to Li-ion batteries (LIBs) due to the cost effective and earth abundant features of K. However, identifying a potential anode for KIBs showing good capacity and stability is still challenging. Because traditional graphite suffers from poor stability owing to the large volume expansion during the insertion/extraction of K ions. Non-graphite carbon is a good candidate because of the disordered nature. A facile high temperature pyrolysis method was adopted to obtain bio-derived carbon materials. Among different kinds of biomass precursors, the porous dandelion seed with nitrogen doping shows the best electrochemical performance with a specific capacity of 168 mAh g−1. The nitrogen-doped carbon presents good K ion adsorption capability and enhanced wettability, which is demonstrated in Fig.S1. Moreover, after introducing activation agent (KOH) in the carbonization process, the capacity in improved to 243 mAh g−1. Meanwhile, the as-prepared carbon material delivers good capacity retention of 91% after 100 cycles. Therefore, the hierarchically porous doped carbon derived from renewable biomass precursor shows great economical potential as KIBs anode. Unlabelled Image • The bio-derived carbon activated by KOH maintain maintain an integrated porous microstructure. • The heteroatoms-doped bio-derived carbon exhibits high specific capacity as K ions anode. • The abundant bio-mass precursor enables large scale preparation of the carbon materials. [ABSTRACT FROM AUTHOR]