In situ constructed MgO parclose-concerted fabrication of Silicon/carbon hybrids via a high-efficiency and expedited electrochemical process in molten salt

The proximate cause postponing silicon/carbon hybrid commercialization is expensive fabricating cost. Herein, a low-cost preparation of silicon/carbon hybrid through a direct electrolytic strategy in molten salt is reported. The all-along existing challenges during the electrolysis of carbon doped silicon that always produces stable SiC phases containing sub-silicon oxide and carbon impurities instead of the desirable silicon/carbon hybrid is overcame by the in -situ constructed MgO physical isolation barrier. The framework of reaction boundary conditions involving the best electrolyte constituent, the silicon-to-carbon ratio and cell voltage range is optimized, achieving a significantly decreased energy consumption of 12,830 kWh t-1 as equivalent to about 902.2 USD per ton of electricity cost, which is merely 10 % of the current market price. The silicon/carbon hybrid exhibits excellent lithium storage capability, as reflected by the superior cycling stability and high reversible capacity (1612.7 mAh g-1 at 0.3 A g-1 after 200 cycles with only 0.17 % per cycle capacity-fading) in half-cells, and high energy density (571.5 Wh kg -1 after 400 cycles) in full cells pairing the as-prepared Si/C hybrid anode with commercial LiNi0.6Co0.2Mn0.2O2 cathode. This work unravels new perspectives on the effective fabrication of silicon/carbon hybrid toward high -performance lithium -ion batteries.