Ordered mesoporous Si microspheres with nitrogen-doped carbon coating for advanced lithium-ion battery anodes

Silicon is considered as a promising anode candidate for the new generation of lithium-ion batteries by virtue of its extensive sources and ultrahigh theoretical specific capacity (4200 mA h g(-1)). The inevitable volume change during the lithiation process will lead to a series of troubles, which has become a major obstacle to the large-scale application of silicon-based electrodes. Herein, silicon microspheres with the ordered mesoporous structure are synthesized through magnesiothermic reduction, which allows void for volume expansion to prevent electrode material from pulverizing. Subsequently, the silicon microspheres are packaged with a polydopamine driven nitrogen-doped carbon layer, which is helpful to maintain the structural stability of electrode materials and enhance the electronic conductivity. The resulting OM-Si@C composite material exhibits remarkable lithium storage properties, which behaves a superior reversible specific capacity of 1751.7 mA h g(-1) at 0.1 A g(-1) after 100 cycles. Furthermore, it also shows excellent rate performance (1183.9 mA h g(-1) at 2 A g(-1)) and long cycle stability. (C) 2019 Elsevier B.V. All rights reserved.