Research Article Li-Ca Alloy Composite Anode with Ant-Nest-Like Lithiophilic Channels in Carbon Cloth Enabling High-Performance Li Metal Batteries

Constructing a three-dimensional (3D) multifunctional hosting architecture and subsequent thermal infusion of molten Li to produce advanced Li composite is an effective strategy for stable Li metal anode. However, the pure liquid Li is difficult to spread across the surface of various substrates due to its large surface tension and poor wettability, hindering the production and application of Li composite anode. Herein, heteroatomic Ca is doped into molten Li to generate Li-Ca alloy, which greatly regulates the surface tension of the molten alloy and improves the wettability against carbon cloth (CC). Moreover, a secondary network composed of CaLi2 intermetallic compound with interconnected ant-nest-like lithiophilic channels is in situ formed and across the primary scaffold of CC matrix by infiltrating molten Li-Ca alloy into CC and then cooling treatment (LCAC), which has a larger and lithiophilic surface to enable uniform Li deposition into interior space of the hybrid scaffold without Li dendrites. Therefore, LCAC exhibits a long-term lifespan for 1100 h under a current density of 5 mA cm-2 with fixed areal capacity of 5 mAh cm-2. Remarkably, full cells paired with practical-level LiFePO4 cathode of 2.45 mAh cm-2 deliver superior performance.

Automated summary

This study introduces the doping of calcium into molten lithium to generate a lithium-calcium alloy, which forms a secondary network on the carbon cloth matrix with lithiophilic channels, enabling stable and uniform lithium deposition and improving the performance of lithium composite materials.