Factors Affecting Voltammetric Responses for Redox-active Solid Layers of Li4Ti5O12 Coated on Electrodes

Analysis for Voltammetric Responses of Molecular-Solid Tetrathionaphthalene Confined on an Electrode

“…Using the mean values of W and ΔW q for eq 8, we could obtain k°0 = 0.59 s À1 for the electrode reaction of the (TTN) 0/1+ couple. The evaluated value of k°0 for the TTN was 2 orders of magnitude smaller than those for the polypyridine Os and Ru complexes confined to the SnO 2 electrode, 13 and 1 ∼ 2 orders of magnitude larger than those for the solid-state LTO layers coated on a graphite electrode (reported previously 7 ). However, in previous literature, very little data regarding the formal rate constants of the electrode reactions for the redox couples in the solid-state have been reported.…”

“…The values obtained for the redox reaction of the (TTN) 0/1+ couple were evaluated as W = 3.39À3.91 (averaged value: 3.67) kJ mol À1 , which was quite similar to that for the LTO layer previously reported. 7 The value of W for the redox reaction of the (TTN) 1+/2+ couple was also evaluated to be 3.09 kJ mol À1 . Values of W evaluated for the (TTN) 0/1+ and (TTN) 1+/2+ couples were largest and positive.…”

“…Therefore, it can be considered that a special attractive force, such as πÀπ interaction among active sites of TTN, might exist, in addition to an electrostatic interaction force between the cationic active site of (TTN) 1+ or (TTN) 2+ and the counteranion of ClO 4 À . Previously, 7 in the case of LTO, it has been considered that there is an electrostatic interaction force in LTO active material for lithium-ion battery, in which a nearest neighbor attractive force of active sites with Li + is taken into account. In the past, some examples regarding W were reported so far: the values of W/(RT) as À0.42 and À2.05 kJ mol À1 for the reversible electrode reaction of quinone derivatives and Fe complexes , α a = α c = 0.50, and ΔW q = À1.39 kJ mol À1 ); in panel (C): ΔW q = 0.00 (trace a), ΔW q = À0.69 (trace b), ΔW q = À1.39 (trace c), ΔW q = À2.78 (trace d), and ΔW q = À6.94 kJ mol À1 (trace e) under the constant values of other parameters (k°0 = 0.59 s À1 , α a = α c = 0.50, and W = 3.54 kJ mol À1 ).…”

“…For the Li 4 Ti 5 O 12 (LTO) solid-state layers as an anode material for the lithium-ion battery, a W value of +4.02 kJ mol À1 of W has been obtained by us. 7 Therefore, in the case of LTO, we concluded that an attractive force among active sites with Li + must be taken into account.…”

“…Such a thermodynamic interaction has been also observed for the Li + -ion insertion materials used for the inorganic electrodes of Li + -ion batteries. 7 Historically, Laviron initially addressed the problem regarding the interaction among redox active sites for surface-confined species. 10À12 Later, the addition of the contribution of the kinetics ABSTRACT: The cyclic voltammetry (CV) of solid-state tetrathionaphthalene (TTN; particles with diameters from a few tens to hundreds of nanometers) confined on electrodes was analyzed quantitatively by considering the inert-zone potential, the thermodynamic and kinetic interactions, and the kinetics of the electrode reaction.…”