Three-Dimensional Double-Walled Ultrathin Graphite Tube Conductive Scaffold with Encapsulated Germanium Nanoparticles as a High-Areal-Capacity and Cycle-Stable Anode for Lithium-Ion Batteries.

The demand for lithium-ion batteries with both high power and high-energy density has attracted widespread attention as energy-storage devices for the increasing demand of consumer electronics, electric vehicles, and grid-scale storage. However, the fabrication of an advanced electrode architecture with high areal capacity, excellent cycling stability, and superior rate performance remains a long-term challenge in the development of advanced electrochemical energy-storage devices. Herein, we design an effective and general strategy to spontaneously encapsulate Ge nanoparticles into a three-dimensional double hydrophilic N-doped ultrathin graphite/void/hydrophobic ultrathin graphite tube network (Ge@3D-DHGT) with control over the position for large specific capacity (1338 mA h g), high rate performance (752 mA h g at 40 C), and superior cycling stability (up to 1000 cycles). Toward the practical application, the as-prepared Ge@3D-DHGT electrode showed a large areal capacity (10 mA h cm under 8 mA cm), which provides a highly promising anode with both high capacity and high rate performance. Importantly, this work provides an approach to fabricate high-areal-capacity anodes with long cycling stability and rapid charge-discharge properties with practical applications in advanced rechargeable batteries.