A strategy associated with conductive binder and 3D current collector for aqueous zinc-ion batteries with high mass loading

Abstract

Abstract In terms of large-scale energy storage, low-cost, environmental-friendly aqueous zinc-ion batteries have great potential, but the mass loading of the cathode materials is still need to be improved for practical application. In order to manufacture VO2 cathodes with high mass loading for using in zinc ion batteries, a strategy associated with conductive binder and 3D current collectors was developed, where PEDOT and carbon fabric were used as the conductive binder and 3D current collector, respectively. As a result, the aqueous batteries assembled with conductive binder would deliver a higher capacity (332 mAh g−1 at 0.62C) compared to non-conducting binder. Even the current density reaching to 92.9C, the aqueous batteries keep a good capacity (255 mAh g−1), which is higher than the cathodes using a conventional binder. The Zn-VO2 batteries also have high energy/power density (177 Wh kg−1 even at 35.4 kW kg−1) and superior cycling stability of up to 2000 cycles. Such excellent rate capability and cycle stability can be illustrated by the capacitive response and fast diffusion coefficient of Zn2+ (~10−9 cm−2 s−1). The VO2 loading can be as high as 15 mg cm−1. Therefore, the use of 3D current collectors and conductive binder in zinc-ion batteries has a good effect which could enable achieve the zinc-ion batteries to have stable cycle life, great rate capability and high energy and power densities. This method provides a versatile approach to building high mass loading cathodes for the aqueous zinc-ion batteries systems with the advantages of environment friendly, low-cost and high security.