Highly loaded gold (Au) nanoseeds with uniform distribution on 3D carbon foam for long-cycle lithium-metal batteries

Abstract

Hybridization of seed materials on the anode is a key approach for inhibiting dendritic lithium growth in lithium-metal batteries. Despite intensive efforts in this field, obstacles remain in realizing high seed loading while maintaining uniformity and dispersibility. Here, we developed a methodology that overcomes this problem through an ultrafast heating/cooling synthetic process and the introduction of numerous anchoring sites via the carbothermal shock (CTS) method, using a nanocellulose-assisted 3D carbon structure. This seed-embedded structure in the carbonized cellulose and CNT (CCC) foam offers high lithium capacity through internal infiltration of the Li host, while also buffering the expanded sheet structure, preventing dendritic Li growth. Additionally, this interlayer adhesion between anode layers and strong adhesive strength between Au nanoseeds and CNT networks facilitate the transport of lithium and electrons and allow for stable reactions during charge and discharge. The cross-sectional scanning electron microscopy results demonstrate that the highly loaded Au nanoseeds with uniform distribution effectively guide lithium to be accommodated inside the conductive layer, rather than on the surface. Furthermore, the Au NPs formed at high temperature (∼1150 °C) are strongly bound to the carbon substrate, resulting in a stable nanoseed structure during alloying and dealloying with Li. As a result, long-term battery performance over 650 cycles at 1 mA cm⁻² was achieved. In addition, the increased kinetics also allow for a significantly longer cycle life of 200 cycles at a high current density of 5 mA cm⁻². We expect that this study will highlight the importance of seed loading and provide a universal method for obtaining high-density nanoseeds in carbon-based materials.