Zn/MnO batteries including an ionic liquid-based gel polymer electrolyte (IL-GPE) have been discharged or discharged and then recharged reaching different states of charge. The Zn electrodes used in these Zn/MnO batteries are studied by HAXPES and synchrotron XRD techniques. Besides, HAXPES measurements are compared with the results obtained by a conventional XPS. Formation of Zn(OH) and ZnO is found in intermediate states of charge during charging and discharging. However, only ZnO is observed in the anode when a full discharging was carried out. Conversely, an entire charging process produces a complete reduction of all Zn species to metallic Zn. In addition, various techniques have confirmed the entrance of Triflate anions and NMP solvent molecules in the electrode, accompanying the Zn cations movement during the charging.

The authors thank the financial support from the Spanish Ministerio de Economía y Competitividad (Ref. ENE2013-48816-C5-3-R and ENE2016-79282-C5-5-R) including FEDER funds and provision of synchrotron radiation facilities at ESRF BM25B line. A.U. thanks F. Séneca (Región de Murcia, Ref: 19882-GERM-15).