Efficient Lithium Storage of Si‐Based Anode Enabled by a Dual‐Component Protection Strategy

Abstract

Si, as a highly competitive anode material for lithium‐ion batteries (LIBs), has gained enormous commercial interests due to its high theoretical capacity, low delithiation potential, and natural abundance. However, its poor cycling stability/electron conductivity seriously restrains its practical applications. To address this problem well, herein, a scalable spray‐drying method is explored to construct an ultrahigh stable 3D Si‐based composite (designed as Si@C‐MX) anode, where the Ti3C2Tx MXene nanosheets (NSs) crump the nano‐Si coated uniformly with an ultrathin carbon layer. Synergistically, the coating carbon layer and Ti3C2Tx NSs as the conductive elastomer constrain/buffer the volume expansion of nano‐Si, avoid direct contact with the electrolyte, build a continuous electronic network for rapid electron transport, and meanwhile improve mechanical properties of the electrodes. Thanks to the dual protection (i.e., carbon coating and Ti3C2Tx NSs) strategy, the resultant Si@C‐MX anode exhibits large reversible capacities, superior rate capability, and long‐duration cycle stability. Additionally, the Si@C‐MX‐based full batteries delivered an energy density of 371.8 Wh kg−1 based on the whole device at 123.9 W kg−1 and a desirable capacity retention with cycling, which convincingly highlights its promising application in advanced LIBs.

Keywords

• carbon coatings
• lithium-ion batteries
• Si anodes
• spray-drying synthesis
• Ti3C2Tx nanosheets