Graphite Based 3D Li Metal Anode for Stable Solid-State Batteries
As one of the most promising energy storage devices in the future, all solid-state lithium metal battery has attracted extensive attention. However, the Li dendrite growth and large volume change during cycling have limited the practical application of Li metal anode. Here, we apply a freestanding interlayer (IL) in between solid-state electrolyte (SSE) and anode to suppress the dendrite growth, and a freestanding 3D anode is designed coupling with excellent ion conductor inside to fabricated a 3D anode with both good ionic conductivity and electronic conductivity. In this work, large MCMB (graphite) particles are utilized as 3D anode host, which provide with free space for Li metal deposition, and KB is used as ion conducting agent, which drive Li metal away from the interface of SSE and make Li deposited in 3D anode. The testing result of this 3D MCMB/KB anode design shows an improved critical current density of 5 mA cm-2. The symmetric cells with both MCMB and MCMB/KB anode show very stable cycling performance with a capacity of 2 mAh cm-2 at 0.5 mA cm-2 for over 1,000h. However, when the capacity is increased to 4 mAh cm-2, the symmetric cell with MCMB anode is shorted in 23 cycles, while the cell with MCMB/KB anode runs stably for over 50 cycles. This 3D anode design offers a promising approach for achieving high energy density and long cycle life solid state Li metal anode cells.