Transporting the hydrogen anion

Ionic Materials Hydrogen cation (H+) transport is common in both biological systems and engineered ones such as fuel cells. In contrast, the transport of hydrogen anions (H−) is far less common and is usually coupled with or compromised by the parallel transport of electrons. Kobayashi et al. examined the transport of H− in a series of rare-earth lithium oxyhydrides (see the Perspective by Yamaguchi). They prevented electronic conduction by using Li+ as a countercation. In an electrochemical cell, the oxyhydride material acted as a solid-state electrolyte for H−, which suggests an alternative avenue for developing energy storage devices. Science , this issue p. [1314][1]; see also p. [1262][2] [1]: /lookup/doi/10.1126/science.aac9185 [2]: /lookup/doi/10.1126/science.aaf3361