Abstract: The hydride ion (H^-), with its strong reducing power and large polarizable ionic radius, can fundamentally avoid the formation of metal dendrites, offering a brand-new route toward safer and higher energy-density solid-state batteries. However, for a long time, finding a solid-state electrolyte that can efficiently conduct hydride ions while effectively blocking electrons at room temperature has been a core challenge. A breakthrough was achieved in 2025, when a core-shell composite material was designed: its inner core facilitates rapid transport of hydride ions, while the outer shell blocks electrons, thereby enabling selective transport of ions over electrons. Based on this new material, the world’s first all-solid-state hydride-ion prototype battery capable of reversible charge/discharge at room temperature was successfully fabricated. This work is discussed from multiple perspectives, including research background, design strategy, microscopic mechanisms, device performance, and future outlook; Its significance for the fields of solid-state ionics and electrochemical energy storage is also appraised.