Mesoporous N-Doped Carbon Nanospheres as Anode Material for Sodium Ion Batteries with High Rate Capability and Superior Power Densities

Optimized sodium ion battery (SIB) carbon anodes with high stability supporting high power densities are a much-needed material class and therefore intensively researched. The optimum graphitization degree to accommodate sodium ions, while providing high conductivity, as well as the influence of particle size distribution or pore sizes on the performance of carbon anodes, is one of the most discussed topics in this field. While a lot of studies have been published discussing these questions, the convoluted nature of these parameters, originating from material synthesis constraints, usually prevents their independent optimization. Based on Mesoporous N-doped Carbon Nanospheres (MPNC) as model carbon material systems, the graphitization temperaturefor spherical particles with a monomodal particle size distribution (approximate to 280 nm) and a narrow pore size distribution (approximate to 30 nm) is optimized for faradaic sodium ion storage (plateau capacity) and electrodes with a very high power density of 2680 W kg-1 at 1000 mA g-1 and a remarkable capacity retention over 2000 cycles of 86 %, only losing 0.04 % of its specific capacity per cycle, are demonstrated. Mesoporous N-doped Carbon Nanospheres (MPNC) with monodisperse particle size, narrow pore size distribution and optimized graphitization temperature are presented as high-performance anode material for faradaic sodium ion storage, achieving a very high power density of 2680 W kg-1 at 1000 mA g-1 and a remarkable capacity retention over 2000 cycles of 86 %. image