Single-Shell Multiple-Core MnO@C Hollow Carbon Nanospheres for Low-Temperature Lithium Storage

Lithium-ionbatteries (LIBs) have been extensively employed ina range of electrical vehicles and portable devices in virtue of theirhigh energy density and stable cycle life. However, poor performanceunder low temperatures hinders their application in cold climatesand regions. Herein, single-shell (carbon) multiple-core (ultra-smallMnO@C nanoparticles) hollow carbon nanospheres (MnO@C@HCS) were preparedby a sacrificial template method, and MnO@C@HCS showed excellent low-temperatureelectrochemical performance. These MnO@C cores with large surfaceareas can shorten diffusion lengths of lithium ions and enhance diffusionrates along their rich grain boundaries, enabling rapid charging/discharging.The hollow carbon nanosphere with a porous shell can block seriousagglomeration of nanoparticles and regulate the amount of electrolytefilled in the hollow nanosphere to reduce side reactions between highlyactive electrode materials and electrolytes. The hollow structureformed between the core and the shell mitigates the volume expansionand contraction during cycling. The MnO@C@HCS anode exhibits highspecific capacities (1027 mAh g(-1) at 0.20 A g(-1)) and high rate performance (353 mAh g(-1) at 10.00 A g(-1)) under room temperature. Furthermore,the MnO@C@HCS anode maintains a satisfactory discharge capacity underlow temperatures (461 mAh g(-1) at 0.05 A g(-1) under -10 & DEG;C, 220 mAh g(-1) at 0.10A g(-1) under -20 & DEG;C, respectively). Thecontribution of pseudocapacitance to the capacity decreases as thetest temperature drops. Our strategy provides a design concept forthe high-performance anode for low-temperature lithium storage.