One-Pot Spray Engineering to Design Na_0.44MnO₂ Cathode Electrodes for High-Rate and Cycle-Stable Na-Ion Batteries

To improve the practical performance of Na-ion batteries, electrode structure engineering provides a new route to improve the electrochemical efficiency of the cathode active material. In this study, we suggest a new route of one-pot spray engineering to design Na_0.44MnO₂ cathodes to realize high-rate and cycle-stable Na-ion battery performance. This technique adjusts the electrode structure from a dense to an open sponge-like morphology during layer-by-layer deposition of the materials. The sponge-like cathode results in improved ion insertion and transport kinetics, thus accelerating the rate capability with increased capacity and high-rate cycling capability (100.1 mAh/g and 90.2% cycling retention after 100 cycles at 5 C). These results highlight the potential for design engineering of cathode structures to achieve high-rate and cycle-stable performance for Na-ion batteries.