Uniformly Confined Germanium Quantum Dots in 3D Ordered Porous Carbon Framework for High‐Performance Li‐ion Battery

Abstract

AbstractAlthough abundant germanium (Ge)‐based anode materials have been explored to obtain high specific capacity, high rate performance, and long charge/discharge lifespans for lithium‐ion batteries (LIBs), their performances are still far from satisfactory due to the intrinsic defects of Ge and the relatively intricate anode structure. To work out these issues, a 3D ordered porous N‐doped carbon framework with Ge quantum dots uniformly embedded (3DOP Ge@NC) as a binder‐free anode for LIBs via a facile polystyrene colloidal nanospheres template‐confined strategy is proposed. This unique structure not only facilitates Li‐ion diffusion and electron transport that can guarantee rapid de/alloying reaction, but also alleviates the huge volume changes during reactions and improves cycling stability. Notably, the resulting anode delivers a high specific reversible capacity (≈1160 mA h g−1 at 1 A g−1), superior rate properties (exceeding 500 mA h g−1 at 40 A g−1), and excellent cycling stability (over 90% capacity retention after 1200 cycles even at 5 A g−1). Furthermore, both the 3DOP Ge@NC anode with high areal mass loading (up to 8 mg cm−2) and the full cell coupled with LiFePO4 cathode display high capacity and cycling stability, further indicative of the favorable real‐life application prospects for high‐energy LIBs.