Affiliation: | 1. Christopher Ingold Laboratory, Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ UK Department of Chemical Engineering, University College London, London, WC1E 7JE UK These authors contributed equally to this work.;2. Department of Chemical Engineering, University College London, London, WC1E 7JE UK These authors contributed equally to this work.;3. Institute of Technological Sciences, Wuhan University, Hubei, Wuhan, 430072 P. R. China;4. Institute of Materials Science, Technische Universität Darmstadt, 64287 Darmstadt, Germany;5. Christopher Ingold Laboratory, Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ UK;6. Department of Chemical Engineering, University College London, London, WC1E 7JE UK |
Abstract: | The electrochemical effect of isotope (EEI) of water is introduced in the Zn-ion batteries (ZIBs) electrolyte to deal with the challenge of severe side reactions and massive gas production. Due to the low diffusion and strong coordination of ions in D2O, the possibility of side reactions is decreased, resulting in a broader electrochemically stable potential window, less pH change, and less zinc hydroxide sulfate (ZHS) generation during cycling. Moreover, we demonstrate that D2O eliminates the different ZHS phases generated by the change of bound water during cycling because of the consistently low local ion and molecule concentration, resulting in a stable interface between the electrode and electrolyte. The full cells with D2O-based electrolyte demonstrated more stable cycling performance which displayed ∼100 % reversible efficiencies after 1,000 cycles with a wide voltage window of 0.8–2.0 V and 3,000 cycles with a normal voltage window of 0.8–1.9 V at a current density of 2 A g−1. |