Strengthening the stability of metal–oxygen (M–O) bonds in catalysts is imperative for the advancement of efficient and durable electrocatalytic water splitting. Herein, using a mild boron-reduction strategy, a self-supported electrode with robust Co–B bonds was constructed. The Co–B@Co(OH)₂–Ru/nickel foam (NF) (Co–B@CRN) electrode demonstrates low overpotentials for alkaline hydrogen evolution reaction (HER, 20 mV) and oxygen evolution reaction (OER, 160 mV) at 10 mA·cm⁻². Furthermore, long-term stability was achieved for over 400 h at 10 mA·cm⁻² and 270 h at 200 mA·cm⁻², respectively. For overall water splitting, the assembled electrolyzer exhibited a low voltage of 1.40 V at 10 mA·cm⁻², with stable operation maintained for over 240 h. Detailed extended X-ray absorption fine structure (EXAFS) characterization verified the mixed valence state of Co and the Co–B coordination environment. Further electronic analysis indicated strong hybridization between Co d-orbitals and B p-orbitals. The B bonding induced a downward shift in the d-band center at the Co site, thereby significantly suppressing metal leaching during catalysis and stabilizing electronic structure regulation. This research shows that the boron reduction strategy offers an effective dynamic regulation mechanism for the electronic structures and coordination environments of transition metals, enabling a highly efficient and stable overall water splitting process.

As the carrier of charge storage, the electrode determines the efficiency of the energy conversion reaction between the battery and the substance. However, with the continuous development of scientific research, electrode preparation is still facing complex technical problems, and it is difficult to achieve a balance in performance, cost, and technology. Based on the ion dissolution and deposition behavior of Mn²⁺/MnO₂ and Al³⁺/Al, a novel cathode-free aqueous ion dissolution/deposition battery is designed, which can contribute 15 mAh at 16 cm² in a voltage window of 0.5–1.8 V. The charge storage and the attenuation mechanism are systematically investigated. The battery model with compensable electrolyte was constructed, and the cycle characteristics of the cathode-free aqueous ion dissolution/deposition battery were optimized, which could achieve 1000 h continuous operation. This system provides a low-cost and high-safety solution for future high-energy density and large-scale energy storage. Future research will focus on optimizing electrolytes, controlling deposition morphology, and improving interface stability to further promote the commercialization of cathode-free batteries.