Low‐Temperature Potassium Batteries Enabled by Electric and Thermal Field Regulation.

Recharging batteries operate at sub‐zero temperature is usually limited by the slow ion diffusion and uneven charge distribution at low temperature. Here, we report a strategy to regulate electric field and thermal field simultaneously, creating a fast and uniform deposition surroundings for potassium ion in potassium metal batteries (PMBs). This regulation is achieved by using a highly ordered 1D nanoarray electrode which provides a dense and flat surface for uniforming the electric field and high thermal conductivity for reducing the temperature fluctuation. Consequently, this electrode could achieve high‐areal capacity of 10 mAh cm−2. Besides, the dependence of potassium nucleation on temperature is unveiled. Furthermore, a full‐cell could steady operate with over 80 % of its room‐temperature capacity at −20 °C. Those respectable performances demonstrate that this strategy is valid, potentially providing guidelines for the rational design of advanced electrodes toward PMBs. [ABSTRACT FROM AUTHOR]