A Soft Lithiophilic Graphene Aerogel for Stable Lithium Metal Anode

The lithium metal anode is one of the most promising anodes for next-generation high-energy-density batteries. However, the severe growth of Li dendrites and large volume expansion leads to rapid capacity decay and shortened lifetime, especially in high current density and high capacity. Herein, a soft 3D Au nanoparticles@graphene hybrid aerogel (Au-GA) as a lithiophilic host for lithium metal anode is proposed. The large surface area and interconnected conductive pathways of the Au-GA significantly decrease the local current density of the electrode, enabling uniform Li deposition. Furthermore, the 3D porous structure effectively accommodates the large volume expansion during Li plating/stripping, and the Li_xAu alloy serves as a solid solution buffer layer to completely eliminate the Li nucleation over-potential. Symmetric cells can stably cycle at 8 mA cm⁻² for 8 mAh cm⁻² and exhibit ultra-long cycling: 1800 h at 2 mA cm⁻² for 2 mAh cm⁻², and 1200 h at 4 mA cm⁻² for 4 mAh cm⁻², with low over-potential. Full cells assemble with a Cu@Au-GA-Li anode and LiFePO₄ cathode, can sustain a high rate of 8 C, and retain a high capacity of 59.6 mAh g⁻¹ after 1100 cycles at 2 C.