Approaches for regulating electrochemical stability of liquid electrolytes in contact with solid-state electrodes are a requirement for efficient and reversible electrical energy storage in batteries. Such methods are particularly needed in electrochemical cells in which the working potentials of the electrodes lie well outside the thermodynamic stability limits of the liquid electrolyte. Here we study electrochemical stability of liquids at electrolyte/electrode interfaces protected by a nanometer-thick, high-electrical band gap ceramic phase. We report that well-designed ceramic interphases extend the oxi-dative stability limits for both protic and aprotic liquid electrolytes, in some cases by as much as 1.5V. It is shown further that such interphases facilitate stable electrodeposition of reactive metals such as lithium at high Coulombic efficiency and in electrochemical cells subject to extended galvanostatic cycling at a high current density of 3 mA cm-2 and at capacities as high as 3 mAh cm-2. High-resolution cryo-FIB-SEM characterization reveals that solid/compact Li electrodeposits anchored by the ceramic interphase are the source of the enhanced Li deposition stability. The results enable a proof-of-concept ‘an-ode-free’ Li metal rechargeable battery in which Li initially provided in the cathode is the only source of lithium in the cell.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-C1-018-02
Acknowledgements: This work was supported by the Department of Energy, Advanced Research Projects Agency - Energy (ARPA-E) through award #DE-AR0000750. M.J.Z. and L.F.K. acknowledge support by the NSF (DMR-1654596). The work made use of electrochemical characterization facilities in the KAUST-CU Center for Energy and Sustainability, supported by the King Abdullah University of Science and Technology (KAUST) through Award # KUS-C1-018-02. Electron microscopy facilities at the Cornell Center for Materials Research (CCMR), an NSF-supported MRSEC through Grant DMR-1120296, were also used for the study. Additional support for the FIB/SEM cryo-stage and transfer system was provided by the Kavli Institute at Cornell and the Energy Materials Center at Cornell, DOE EFRC BES (DE-SC0001086).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.