Overpotential / V Log i 0 = -3.7 0.895 V 0.883 V 0.870 V 0.860 V 0.851 V 0.844 V 0.837 V 0. cm s -1 and 1.3 × 10 -2 cm s -1 respectively, for the oxidation reaction of AcFc. Similarly, k o of Fe(acac) 3 at 25 o C and 0 o C were calculated to be 3.3 × 10 -3 cm s -1 and 1.3 × 10 -3 cm s -1 respectively, for the reduction of Fe(acac) 3 . This kinetic parameter of AcFc is greater than Fe(acac) 3 , is therefore expected to lead to fast electron transfer processes in the battery test.