Co@CoAl‐Layered Double Hydroxide/Nitrogen‐Doped Graphene Composite Catalyst for Al−H 2 O‐Based Batteries: Simultaneous Hydrogen Production and Electricity Generation

Currently, the low energy efficiency of water electrolysis has compelled research toward the development of novel and energy‐effective strategies for low‐cost H 2 generation. In this context, we report a new concept of simultaneous H 2 and electricity generation by separating out the exothermic self‐sustained Al−H 2 O reaction via electrochemistry. In addition, to catalyze the cathodic water reduction reaction, a single‐pot and environmentally benign synthesis method is adopted. It results in the design of an electrocatalyst composed of Co@CoAl‐layered double hydroxide core‐shell nanospheres anchored over in situ generated N‐doped graphene. Toward the water reduction reaction, the designed catalyst shows a negative voltage shift of mere around 113 mV with respect to the commercial Pt/C catalyst to reach the benchmark 10 mA cm −2 , with excellent stability of approximately 86 % voltage retention after 12 h of continuous operation. The catalytic superiority of our material is evident when taken for battery‐level testing; the fabricated device was able to deliver an average output voltage of around 0.95 V at a discharge current density of 5 mA cm −2 along with H 2 liberation, which was also detected and quantified through gas chromatography.