Wadsley-Roth Phase Niobium-Based Oxide Anode Promising High Power and Energy Density Aqueous Li-Ion Batteries

Abstract

Intermittent and instantaneous renewable energy is urgently needed to develop intrinsic safe electrical energy storage technology with high power-energy density. Aqueous lithium-ion batteries (ALIBs) are a promising integration due to their nonflammable nature. Nevertheless, restricted by the anode materials, their energy density has a considerable gap from that of their nonaqueous counterparts. Herein, Wadsley-Roth phase niobium-based oxides (M–Nb–O) are attempted for aqueous Li-ion anodes for the first time. By pairing with the representation of the M–Nb–O anode (Zn2Nb34O87), the output voltage, energy density, and power density of ALIBs increased remarkably, and long-term cycle life improved significantly. Individually, the energy-type full cell (NCM811//Zn2Nb34O87) yields high-record density energy (191.5 Wh kg–1) with a high average discharge voltage of ∼2.25 V, and the power-energy type full cell (LiMn2O4//Zn2Nb34O87) exhibits a superior rate capability with a high energy density of 30.0 Wh kg–1 at an ultrahigh powder density of 16 489 W kg–1.