Integrating Dually Encapsulated Si Architecture and Dense Structural Engineering for Ultrahigh Volumetric and Areal Capacity of Lithium Storage

High-theoretical-capacity silicon anodes hold promise in lithium-ion batteries (LIBs). Nevertheless, their huge volume expansion (∼300%) and poor conductivity show the need for the simultaneous introduction of low-density conductive carbon and nanosized Si to conquer the above issues, yet they result in low volumetric performance. Herein, we develop an integration strategy of a dually encapsulated Si structure and dense structural engineering to fabricate a three-dimensional (3D) highly dense Ti