| Popis: |
Pseudocapacitive materials with high-rate behavior of lithium-ion charge storage offer a pathway to narrow the kinetics gap with capacitive porous carbon cathode toward lithium-ion capacitors both with high energy and high power densities. However, most of pseudocapacitive materials are subject to their relatively high redox potential and/or the morphological requirement of nanoscale, thus resulting in an undesirable decrease in energy density from either gravimetric or volumetric sides. Here, we demonstrate that lithium-rich disordered rock salt vanadium oxide (DRX-Li3V2O5) exhibits typical pseudocapacitive behaviors within a low working potential range between 0.1 V and 2 V versus a Li/Li+ reference electrode. The pseudocapacitive behaviors of DRX-Li3V2O5 is inherent to its bulk form, which mainly arises upon a percolating network that offers three-dimensional lithium-ion transport pathways confirmed by the Monte Carlo simulations. A lithium-ion capacitor is further assembled by combing this pseudocapacitive DRX-Li3V2O5 anode with a capacitive activated carbon cathode, yields a cell voltage of 4.0 V and both high values of energy and power densities, higher than or comparable to that of the state-of-art lithium-ion capacitors based on graphite and other pseudocapacitive materials. Lithium-ion capacitor based on this high-rate and low-cost DRX-Li3V2O5 anode is ready for commercialization. |
