Investigation of Reversible Li Insertion into LiY(WO4)(2)by Gupta, Asha; Singh, Preetam; Mullins, C. Buddie; Goodenough, J. B.
The layered structure of LiY(WO4)(2) accommodates a reversible insertion of two Li per formula unit near 1.5 V versus Li+/Li-0. At low charge/discharge rates, there is a voltage step on charge from 1.55 to 1.6 V at one Li extraction per formula unit, the efficiency of electrical energy storage is reasonable, and the specific capacity is 90 m Ah g(-1). At higher rates, less than one Li per formula unit is inserted reversibly. A solid-electrolyte interphase (SEI) is formed in the voltage range 1.2 < V < 1.4 V versus Li+/Li-0 on the initial charge.