Future renewable energy integrated grid systems require rechargeable batteries with low cost, high safety, and long cycle life. The much higher abundance of sodium and potassium compared to lithium in earth crust indicates that rechargeable sodium and potassium batteries are attractive replacements for lithium-ion batteries. Rechargeable potassium batteries have gained tremendous attention during the past decade. However, the development of rechargeable potassium batteries is still in its infancy. This review summarizes the recent technological developments in rechargeable potassium batteries. First, we summarize the latest achievements of active materials design, mechanistic understanding, and exploration of new active materials. We propose new directions in tuning the architecture and enhancing the electrochemical performances of high-performance anodes and cathodes. Second, we also summarize the advances that have been achieved in the new configurations of rechargeable potassium battery systems (potassium-ion capacitors, potassium dual ion batteries, potassium-sulfur batteries, and potassium-oxygen batteries). Finally, we propose future directions and design strategies that could be employed to advance rechargeable potassium batteries toward commercial applications.