Li 2 MnO 3 : A Catalyst for A Liquid Cl 2 Electrode in Low-Temperature Aqueous Batteries.

Li MnO has been contemplated as a high-capacity cathode candidate for Li-ion batteries; however, it evolves oxygen during battery charging under ambient conditions, which hinders a reversible reaction. However, it is unclear if this irreversible process still holds under sub-ambient conditions. Here, we evaluated the low-temperature electrochemical properties of Li MnO in an aqueous LiCl electrolyte and observed a reversible discharge capacity of 302 mAh/g at a potential of 1.0 V versus Ag/AgCl at -78 °C with good rate capability and stable cycling performance, in sharp contrast to the findings in a typical Li MnO cell cycled at room temperature. However, our results reveal that the capacity does not originate from the reversible oxygen oxidation in Li MnO but the reversible Cl (l)/Cl (aq.) redox from the electrolyte. Our results demonstrated the good catalytic properties of Li MnO to promote the Cl /Cl redox at low temperatures. This article is protected by copyright. All rights reserved.