V, the oxidative peak shift over 100 cycles is reduced to only 50 mV. In both cases, the second charging peak is unaffected. Notably, the capacity fade in this niobium tungsten oxide differs from the titanium niobium oxide TiNb24O62, which shows increasing polarization between its more pronounced reduction and oxidation peaks. The mechanistic difference in degradation between decreasing dQ/dV intensity vs. peak shift is consistent with active material loss vs. polarization, respectively.