Natural Clay-Derived SiO _<i>x</i> @Graphene Aerogel Integrated through an Oxygen Bridge for Advanced Lithium Storage

Silicon oxide (SiOx) materials show promising potential as anode materials for lithium-ion batteries. However, the development of SiOx materials has been significantly limited by their intrinsic disadvantages, including poor mechanical properties, low conductivity, and limited cycling capability. Herein, we report a facile and cost-effective synthesis method to develop SiOx nanoparticles anchored on graphene aerogel (SiOx@GA) from naturally abundant attapulgite (ATP) clay, which exhibits significant potential for lithium-ion batteries. Through extensive characterizations and density functional theory (DFT) calculations, we identify that clay-derived SiOx with a small particle size is grafted on defective graphene through forming the oxygen bridge, which allows efficient electron transfer from conductive graphene nanosheets to insulator SiOx. Furthermore, strong interactions can also prevent the over-reduction of SiOx on GA, allowing it to combine the advantages of silicon and silicon oxides to suppress the volume expansion and increase the overall stability of the anode materials. As a result, the lithium-ion batteries with the SiOx@GA anode deliver an excellent electrochemical performance with a high specific capacity of 602 mAh g–1 and prolonged durability for over 1200 cycles at 1 A g–1. This work provides a practical and viable strategy to utilize natural resources for developing large-scale and low-cost SiOx-based anode materials for high-performance lithium-ion batteries.