Nano-size porous carbon spheres as a high-capacity anode with high initial coulombic efficiency for potassium-ion batteries

can be retained after 1500 cycles, respectively. Quantitative analysis reveals that this optimized structure leads to an enhanced surface-controlled contribution, resulting in fast potassiation kinetics and electronic|ionic conductivities, which are regarded as essential features for potassium storage. Our findings in this work provide an efficient strategy to significantly improve potassium storage capacity while maintaining a high ICE for hard carbon electrodes.