Adán-Más, AlbertoTaryba, MarynaMoura E Silva, TeresaGuerlou-Demourgues, LilianeMontemor, M.F.2020-04-232020-04-232020-04-23ADÁN-MÁS, Alberto; [et al] – In-situ localized pH, pNa and dissolved O2 measurements during charge-discharge of mixed Ni–Co hydroxide electrodes. Journal of The Electrochemical Society. ISSN 0013-4651. Vol. 167, N.º 8 (2020), pp. 1-90013-46511945-7111http://hdl.handle.net/10400.21/11513This work reports, for the first time, the use of ion-selective localized electrochemical techniques to elucidate the charge-discharge mechanism of nickel-cobalt hydroxide electrodes for electrochemical energy storage. The charge-discharge mechanism of electrodeposited nickel-cobalt hydroxide electrodes was studied in Na2SO4 0.05 M by localized in situ measurements of pH, pNa and dissolved O2 during cyclic voltammetry. Local pH and pNa distributions were recorded using micro-potentiometric sensors with liquid membrane, while dissolved O2 was monitored using a fiber-optic microsensor. These original results highlight how localized potentiometry can provide new insights to better understand the charge mechanism of metal (hydr)oxide electrodes by directly measuring the concentrations/activities of relevant species at the electrode-electrolyte interface during charge-discharge.engIon-selectiveLocalized electrochemical techniquesCharge-discharge mechanismNickel-cobalt hydroxide electrodesElectrochemical energy storagejournal article10.1149/1945-7111/ab8924