Boron-Doped and Carbon-Controlled Porous Si/C Anode for High-Performance Lithium-Ion Batteries

Silicon is a promising anode material for next generation lithium-ion batteries due to its high capacity and low discharge potential. Commercial silicon anodes are normally integrated with high graphite content to overcome their low electrical conductivity and huge cycling-induced volume change. However, this weakens the high specific capacity advantage of the silicon anode. Herein, a facile method based on the dealloying reaction of Mg2Si with CO2 and B2O3 was demonstrated for the synthesis of porous boron-doped silicon with low carbon content (pBSi-LC). Furthermore, the pBSi-LC anode showed high initial Coulombic efficiency of 89.3%, excellent rate performance (reversible capacity of 842 mAh g–1 at a high current density of 5A g–1), and long cycle stability (reversible capacity of 860 mAh g–1 at a current density of 2 A g–1 after 250 cycles).