Potassium-ion batteries (PIBs) can be regarded as one of the most emerging energy storage devices alternative to current Li-ion batteries (LIBs), due to their resourceful, environment-friendly, and economic merits. For anode in PIBs, the recent researches have mainly focused on carbonaceous materials due to their high electric conductivity and low cost. Nevertheless, the capacities of carbonaceous materials are not satisfactory and cannot meet the growing demand for higher energy density batteries, which have seriously hindered their practical application. Recently, the alloy type materials such as Sn, Sb, Ge, and P have attracted much attention due to their superior capacity. Among various alloy type materials, Sb is a potential anode material for PIBs with a high theoretical capacity of 660 mA h g^-1. However, a large volumetric change of ~400% during the alloying/dealloying processes may cause the fracture of active material and loss of electrical contact, leading to rapid capacity fading. To address this issue, numerous strategies have been proposed to mitigate the stress induced by volume change and enhance the electrochemical performance of Sb-based electrodes. An efficient and simple strategy is to synthesize carbon coated porous morphology and structure in nanoscale.

In the present study, we have successfully prepared a Nano porous Sb/C composite through a simple carbothermal reduction method. Fig.1 represents the XRD pattern and morphology of the synthesized nanoporous Sb/C composite. Further, the electrochemical performance of nanoporous Sb/C electrode was studied for the application as an anode material for PIBs. The nanoporous Sb/C electrode exhibited excellent electrochemical characteristics in terms of high specific capacity, excellent cyclability, and good rate capability. The superior performance of Sb/C electrode is attributed to the original high capacity of Sb active materials as well as the mitigation of stress and the improvement of electrical conductivity inside electrode by employing carbon coating. The effect of the alloying/dealloying process on the crystal structure of Sb/C was examined by the ex-situ XRD patterns recorded in various stages of discharge and charge. We consider that this work can provide a guideline to open up new research opportunities in the development of PIBs.