Regulation of the surface activity of carbon anodes for rationalization of potassium storage

The gradient temperature was manipulated to construct hollow irregular carbon spheres with regulated intrinsic defects and surface area targeting favorable potassium storage. An enlarged surface area, increased intrinsic defects, and superior conductivity induced more surface-active interfaces. These actions facilitated a high reversible capacity as well as excellent cycling stability. Well-designed carbon anodes originating from a MgO-template approach and annealing regulation were featured by ample defect sites and interfaces, thereby leading to increased electrochemical functions for guiding K-ion evolution behavior.