[21p-438-1~12] 9.4 Thermoelectric conversion

[21p-438-9] Temperature Coefficient of Redox Potential of LiFePO₄

〇Yuya Fukuzumi¹, Yoyo Hinuma², Yutaka Moritomo^3,4 (1.Grad. Sch. Pure and Appl. Sci., Univ. Tsukuba, 2.Ctr. Frontier Sci., Chiba Univ., 3.Fac. Pure and Appl. Sci., Univ. Tsukuba, 4.TREMS, Univ. Tsukuba)

Keywords:thermoelectric converson, lithium ion secondary battery, oxide

Temperature coefficient of redox potential (α = ∂V/∂T, where V and T are redox potential and temperature, respectively) is a significant material parameter, which enables us to convert thermal energy into electric power. In this study, one of the famous electrode materials for lithium ion secondary batteries, Li_xFePO₄, was evaluated as α = 0.9 mV/K. Furthermore, entropy of LiFePO₄ and that of FePO₄ were obtained by using first principle calculation. The difference in entropy (0.30 meV/K) represents α obtained by our experiment considering solution effect of electrolyte.