Restricted by their energy storage mechanism,current energy storage devices have certain drawbacks,such as low power density for batteries and low energy density for supercapacitors.Fortunately,the nearest ion capacitors,such as lithium-ion and sodium-ion capacitors containing battery-type and capacitor-type electrodes,may allow achieving both high energy and power densities.For the inspiration,a new zinc-ion capacitor (ZIC) has been designed and realized by assembling the free-standing manganese dioxide-carbon nanotubes (MnO2-CNTs) battery-type cathode and MXene (Ti3C2Tx) capacitortype anode in an aqueous electrolyte.The ZIC can avoid the insecurity issues that frequently occurred in lithium-ion and sodium-ion capacitors in organic electrolytes.As expected,the ZIC in an aqueous liquid electrolyte exhibits excellent electrochemical performance (based on the total weight of cathode and anode),such as a high specific capacitance of 115.1 F g-1 (1 mV s-1),high energy density of 98.6 Wh kg-1 (77.5 W kg-1),high power density of 2480.6 W kg-1 (29.7 Wh kg-1),and high capacitance retention of～ 83.6％ of its initial capacitance (15,000 cycles).Even in an aqueous gel electrolyte,the ZIC also exhibits excellent performance.This work provides an essential strategy for designing next-generation high-performance energy storage devices.