Regulating and Unraveling Electrochemical Behavior of Hierarchically‐Densifying Mesoporous Apocynum Carbon for High performance Supercapacitor

Abstract

The commercial carbon‐based supercapacitor with high power ability ( ~5 kW kg‐1) is still unable to fulfill the superhigh power requirement of specific power‐type equipments ( >20 kW kg‐1), such as rail transit facilities, electromagnetic and laser equipment. To unravel the structure‐activity relationship and electrochemical behavior of power‐type densifying carbon is a key to overcome the contradiction of the suitable mesoporous ratio and highly‐densifying features toward the superhigh power requirement. Here, we built the hierarchically‐densifying mesoporous apocynum carbon (HDMC) with optimized mesoporous ratio by hierarchical activation method and uncover the microscopic surface carbon network stacking mechanism and the macroscopic carbon skeleton densification assembly mechanism. The highly‐densifying skeleton features (high tap density of0.387 g cm‐3) and high mesoporous ratio (23.1%) properties were proved to be co‐existed in HDMC, which is in favour of rapidly ion/electron transferring toward electrochemically‐improving power behavior of HDMC. HDMC‐based supercapacitor could provide super‐high power density (33.5 kW kg‐1) and high volume power density (9.37 kW L‐1), more than those of commercial YP‐50F (14.9 kW kg‐1 @ 4.63 kW L‐1). Therefore, this work provides a synergistic strategy to incorporate the properties of mesoporous and densifying, and reveals its electrochemical behavior toward the further application of power‐type supercapacitors.