Confinement Synthesis Based on Layered Double Hydroxides: A New Strategy to Construct Single-Atom-Containing Integrated Electrodes

Highly efficient and low-cost electrodes have a key role in the development of advanced energy devices such as fuel cells and metal-air batteries. However, electrode performance is typically limited by low utilization of active sites, which causes a considerable drop in energy density. To overcome this issue, a single-atom-containing integrated electrode is developed through a confinement synthesis strategy by using organic molecule-intercalated layered double hydroxides (LDHs) as precursors. The as-prepared integrated electrode has a well-defined nanosheet array structure with a homogeneous anchored single atomic Co catalyst and many exposed hierarchical pores. Moreover, the coordination environment of single atoms (Co-N or Co-S) is precisely controlled by regulating the type of interlayer molecules in the LDHs. Consequently, the optimized electrode exhibits high bifunctional activity toward both the oxygen reduction and oxygen evolution reactions. This electrode is directly assembled into an all-solid-state zinc-air battery that showed outstanding flexibility and long-term charge/discharge stability. Because of the versatility of LDH materials, it is expected that the proposed strategy can be extended to the construction of other integrated electrodes for high-performance energy storage and conversion devices.

Automated summary

This study introduces a single-atom-containing integrated electrode developed through a confinement synthesis strategy, which is highly efficient and low-cost, for applications in advanced energy devices such as fuel cells and metal-air batteries. Through optimized design, the electrode exhibits high bifunctional activity toward both the oxygen reduction and oxygen evolution reactions, achieving outstanding performance in an all-solid-state zinc-air battery.