Nanomesh NiO-modified carbon cloth for highly efficient self-supporting potassium metal anodes

Potassium metal is one of the most promising anode materials for potassium-ion batteries owing to its low cost and ability to withstand high current density and relatively low operating potential. However, it is restricted from being used in practical implementations because of its high reactivity and disordered dendrite growth. To circumvent these issues, we stabilize potassium metal anodes by growing NiO with high potassium affinity and interconnected network porous structure on carbon cloth fibers (CC-NiO). A symmetric cell assembled from a composite material formed by infiltrating molten K into CC-NiO (K@CC-NiO) can cycle stably for 1840 h at a low overpotential of 33 mV. Furthermore, the first-cycle discharge capacities of the full batteries with carbon nanotubes-interwoven KFeSO4F microspheres (KFSF@CNTs) and perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) as the cathodes are 101.4 and 105.1 mAh g−1, respectively. The capacity retention of KFSF@CNTs||K@CC-NiO full battery after 1000 cycles is 79.3 %, and the capacity retention of PTCDA||K@CC-NiO full battery after 800 cycles is 70.2 %. The strategy of utilizing NiO as an efficient potassium metal nucleation anchor opens up a new direction for the development of high-energy and long-cycle-life potassium metal batteries.