In-situ construction of barium-induced cathode electrolyte interphase to enable mechanostable high-performance zinc-ion batteries

Vanadium-based compounds with open frameworks are recently the subject of intensive research as cathodes for aqueous zinc-ion batteries (AZIBs) with the advantages of high safety and high energy density. However, the spontaneous vanadium dissolution from a cathode and the formation of by-products in aqueous electrolytes are challenging issues that must be addressed as they cause substan-tial capacity degradation and inadequacy in cycle life. Here, we develop an efficient way to suppress vanadium dissolution via an in-situ formed cathode electrolyte interface (CEI) by incorporating barium ions in the vanadium framework. Such barium ions increase the interlayer structure and act as a sacrificial agent to form an in-situ BaSO4 CEI that reduces vanadium dissolution while enhancing the diffusion kinetics. As a cathodic active material, Ba-V6O13 nanobelts show a specific capacity of 305 mAh g(-1) at 0.1 A g(-1) and an energy density of 213 Wh/kg, offering excellent reversible capacity retention of 99.94% per cycle. Besides, it operates stably even after physically cutting the device and exhibits excellent interfacial stability. This work presents an innovative strategy to accelerate the commerciali-zation of safe, fiexible AZIBs.(c) 2023 Elsevier Ltd. All rights reserved.