Faradaically selective membrane for liquid metal displacement batteries

Yin, H.*; Chung, B.*; Chen, F.*; Ouchi, Takanari*; Zhao, J.*; Tanaka, Nobuyuki; Sadoway, D. R.*

Nature Energy (Internet), 3(2), p.127 - 131, 2018/02

https://doi.org/10.1038/s41560-017-0072-1

We disclose a new porous electronically conductive membrane, which achieves chemical selectivity by preferred faradaic reaction. This shift in membrane mechanism grants access to a variety of heretofore forbidden choices for positive and negative electrode metals and allows the battery to charge-discharge at high rate without degradation. Fitted with a porous membrane of TiN, a displacement cell comprising a Pb positive electrode, a Li Pb negative electrode, and LiCl-KCl eutectic electrolyte was cycled at 410C and exhibited a coulombic efficiency of 92%. The capacity fade rate was measured to be 0.00172% per cycle, which is tantamount to retention of greater than 94% of initial capacity after 10 years. Most significant from the standpoint of scalability, we show that the faradaic membrane can be fashioned out of metal so as to be mechanically durable and therefore easily mass-produced at large scale with a thin cross-section for minimal ohmic drop in cell voltage.