Stabilizing polymer electrolytes in high-voltage lithium batteries

Abstract

Electrochemical cells that utilize lithium and sodium anodes are under active study for their potential to enable high-energy batteries. Liquid and solid polymer electrolytes based on ether chemistry are among the most promising choices for rechargeable lithium and sodium batteries. However, uncontrolled anionic polymerization of these electrolytes at low anode potentials and oxidative degradation at working potentials of the most interesting cathode chemistries have led to a quite concession in the field that solid-state or flexible batteries based on polymer electrolytes can only be achieved in cells based on low- or moderate-voltage cathodes. Here, we show that cationic chain transfer agents can prevent degradation of ether electrolytes by arresting uncontrolled polymer growth at the anode. We also report that cathode electrolyte interphases composed of preformed anionic polymers and supramolecules provide a fundamental strategy for extending the high voltage stability of ether-based electrolytes to potentials well above conventionally accepted limits.

Proton Intercalation/De‐Intercalation Dynamics in Vanadium Oxides for Aqueous Aluminum Electrochemical Cells

“…We report further that selectivity of V 2 O 5 for various cations in more basic electrolytes is largely regulated by the relative ion concentration and charge density. Finally, we show that an interlayer membrane that facilitates selective cation transport into the V 2 O 5 cathode promotes reversibility of the cathode by simultaneously enabling cation de‐solvation and by preventing anion insertion into V 2 O 5 .…”

Nanostructured liquid-crystalline Li-ion conductors with high oxidation resistance: molecular design strategy towards safe and high-voltage-operation Li-ion batteries

“…Because advanced Li-ion batteries require electrochemical stability in the potential range of 0-5.0 V vs. Li/Li + for full charge-discharge of positive and negative electrode materials, improvement of the oxidation resistance of electrolytes in Li-ion batteries have been studied. [29][30][31][32][33][34][35][36][37] Our previous molecular design for LC electrolytes in Li-ion batteries 9 was not sufficient in terms of electrochemical stability.…”

Polyethylene Oxide-Based Composites as Solid-State Polymer Electrolytes for Lithium Metal Batteries: A Mini Review

“…As the most potential anode material, Li-metal possesses advantages such as high theoretical capacity (3,860 mA h g −1 ), negative potential [−3.04 V vs. standard hydrogen electrode (SHE)], and low density (~0.59 g cm −3 ) (He et al, 2018 ; Zhao C. Z. et al, 2019 ). However, Li-metal batteries (LMBs) with liquid electrolytes cannot coordinate a high energy density with excellent electro-stability for real applications (Choudhury et al, 2019b ). The robustness and integrity of the electrode–electrolyte interface through cycling ensure the efficacy of the whole cell (Maleki Kheimeh Sari and Li, 2019 ).…”