Two Dimensional V2O5 Nanosheets As an Advanced Cathode Material for Realizing Low-Cost Aqueous Aluminum Ion Battery

Abstract

Aluminum-ion batteries (AIBs) are rapidly gaining momentum for the next generation energy storage industry because of its various advantages. In this paper, interconnected sheets-like morphology of low cost V2O5 is being reported as a cathode material to improve the capacity, rate capability, and cycling stability of Al battery (AIB). Benefiting from the unique two-dimensional sheet morphology, the V2O5 cathode are able to deliver an initial discharge capacity of ~ 140 mAh g-1, at high current density of 0.5 A g-1, with an excellent capacity retention of 96 % after 1000 cycles at 1 A g-1, which is amongst the best cathode performances reported for aqueous AIBs. The high energy storage mechanism of V2O5 is based on the facile intercalation and deintercalation of the tri-valent Al ions from the electrolyte through the electrode material during discharging and charging processes, respectively. Notably, the smaller lattice expansion (~1.4 %) of V2O5, indicate the expansion and contraction of the crystal structure occur reversibly during the discharge-charge process. The stability of the material is established by analyzing the XRD patterns of the material after cycling. Such studies have remained ignored in AIBs till date.