Promoting the Performance of Li-CO₂ Batteries via Constructing Three-Dimensional Interconnected K⁺ Doped MnO₂...

Nowadays, Li-CO₂ batteries have attracted enormous interests due to their high energy density for integrated energy storage and conversion devices, superiorities of capturing and converting CO₂. Nevertheless, the actual application of Li-CO₂ batteries is hindered attributed to excessive overpotential and poor lifespan. In the past decades, catalysts have been employed in the Li-CO₂ batteries and been demonstrated to reduce the decomposition potential of the as-formed Li₂CO₃ during charge process with high efficiency. However, as a representative of promising catalysts, the high costs of noble metals limit the further development, which gives rise to the exploration of catalysts with high efficiency and low cost. In this work, we prepared a K⁺ doped MnO₂ nanowires networks with three-dimensional interconnections (3D KMO NWs) catalyst through a simple hydrothermal method. The interconnected 3D nanowires network catalysts could accelerate the Li ions diffusion, CO₂ transfer and the decomposition of discharge products Li₂CO₃. It is found that high content of K⁺ doping can promote the diffusion of ions, electrons and CO₂ in the MnO₂ air cathode, and promote the octahedral effect of MnO₆, stabilize the structure of MnO₂ hosts, and improve the catalytic activity of CO₂. Therefore, it shows a high total discharge capacity of 9,043 mAh g^-1, a low overpotential of 1.25 V, and a longer cycle performance.