Germanium quantum dots embedded in N-doping graphene matrix with sponge-like architecture for enhanced performance in lithium-ion batteries

Germanium quantum dots embedded in a nitrogen-doped graphene matrix with a sponge-like architecture (Ge/GN sponge) are prepared through a simple and scalable synthetic method, involving freeze drying to obtain the Ge(OH) ₄/graphene oxide (GO) precursor and subsequent heat reduction treatment. Upon application as an anode for the lithium-ion battery (LIB), the Ge/GN sponge exhibits a high discharge capacity compared with previously reported N-doped graphene. The electrode with the as-synthesized Ge/GN sponge can deliver a capacity of 1258 mAhg^-1 even after 50 charge/discharge cycles. This improved electrochemical performance can be attributed to the pore memory effect and highly conductive N-doping GN matrix from the unique sponge-like structure. Sponge effects: Germanium quantum dots embedded in a nitrogen-doped graphene matrix with a sponge-like architecture are designed (see figure). They exhibit an enhanced electrochemical performance for Li-ion batteries owing to their unique structural features.