fig3

Figure 3. Electrochemical properties of Nb₄W₇O₃₁/Li half cell: (A) discharge/charge curves at various current rates, (B) rate capability, and cyclic stability at (C) 1C and (D) 10C (after rate-capability test). Electrochemical properties of LiFePO₄//Nb₄W₇O₃₁ full cell: (E) charge/discharge curves at various current rates, (F) rate capability, and (G) cyclic stability at 1C (after rate-capability test, inset: LED lit up by full cell). (H) dQ/dV curves of Nb₄W₇O₃₁/Li half cell at 0.1C.