Enhancing low-temperature performance and suppressing cathode dissolution in aqueous zinc-ion batteries: local structure and electrochemical crosstalk control of V2O5

Abstract

Achieving an in-depth understanding of the nexus between temperature and phase transitions is paramount for advancing the electrochemical efficiency of aqueous zinc ion batteries. Yet, the intricacies of electrochemical interactions, particularly those associated with the structural evolution over extended periods, remain enigmatic. In this research, we leverage V₂O₅ as an initial structural model of crystals to demystify the kinetics of electrode reactions and the decay mechanism of global electrochemical degradation by meticulously controlling the crystal defects via applying different mechanical grounding intensities. It is noted that the grounding V₂O₅ (GVO) can exhibit a stable crystal structure that suppresses the dissolution/shuttling of vanadium and mitigates Zn anodes by-products caused by electrochemical processes. Thus, the GVO is utilized as the cathode material, achieving excellent Zn storage capacity at both room temperature and low temperatures, e.g., 380 and 246 mA h g⁻¹ at room temperature and −20°C, respectively. Remarkably, the GVO cathode retains a specific capacity of 160 mA h g⁻¹ with a capacity retention rate of 99% after 1500 cycles at −20°C and 1 A g⁻¹. This work provides a novel insight into the electrochemical crosstalk behavior of aqueous zinc-ion batteries (AZIBs) in a wide range of temperatures.