High Specific Energy Density Aqueous Lithium-Metal Chloride Rechargeable Batteries

• Published in: Journal of the Electrochemical Society 2017-01, Vol.164 (9), p.A1958-A1964
• Main Authors: Morita, Yoshinori, Watanabe, Shinya, Zhang, Peng, Wang, Hui, Mori, Daisuke, Matsuda, Yasuaki, Yamamoto, Osamu, Takeda, Yasuo, Imanishi, Nobuyuki
• Format: Article
• Language: English
• ISSN: 0013-4651; 1945-7111
• DOI: 10.1149/2.0881709jes

Here we show the feasibility of a novel high energy density battery with a Li anode and a MCl2 (M = Fe, Co, Ni, Cu, and Zn) aqueous cathode separated by a water-stable NASICON-type lithium-ion conducting solid electrolyte of Li1.4Al0.4Ge0.2Ti1.4(PO4)3 (LAGTP). The Li/MCl2 (M = Co, Ni, and Zn) aqueous solution with LiCl cells were successfully charged and discharged. In contrast, the Li/MCl2 (M = Fe and Cu) cells were discharged, but they could not be charged, because FeCl2 and CuCl2 reacted with lithium-ions to produce an insoluble compound. The Li/CoCl2 and Li/NiCl2 cells showed discharge cathode capacities of 326 and 412 mAh g−1 at 60°C and 4.0 m A cm−2, respectively, which correspond to 78 and 100% to the theoretical capacity, respectively. The estimated specific energy densities calculated using the mass of cell components with a 0.1 mm thick LAGTP separator (except the packaging) were 617 and 670 Wh kg−1 for the Li/CoCl2 and Li/NiCl2 cells, respectively, which are approximately two times higher than those for conventional lithium-ion batteries.