High performance porous Si@C anodes synthesized by low temperature aluminothermic reaction

A low temperature (210 degrees C) aluminothermic reaction process using a eutectic mixture of AlCl3 and ZnCl2 as the mediator has been developed to synthesize porous silicon (Si) as an anode for lithium (Li)-ion battery applications. With carbon pre-coating on the porous SiO2 precursor, carbon coated porous Si (p-Si@C) core-shell structured anodes could be obtained with architecture and morphology similar to that of the porous SiO2 precursor. The carbon coating network not only facilitates the electron and Lithorn ion transportation, but also offers good mechanical support minimizing the particle pulverization that is associated with the large volume change of Si during lithiation/delithiation. As a result, p-Si@C anode demonstrates a high specific capacity of similar to 2100 mAh g(-1) at the current density of 1.2 A g(-1) and significantly improved capacity retention of similar to 89% over 250 cycles, which is much better than that of p-Si. Therefore, p-Si@C is promising anode for high-energy-density Li-ion batteries. The similar low temperature synthesis approach can also be used to prepare other functional materials. (C) 2018 Elsevier Ltd. All rights reserved.