Multi-layered Sn and Hard Carbon Architectures for Long-Term Stability and High-Capacity Lithium-Ion Battery Anodes

Tin (Sn) is a promising candidate for lithium-ion batteries (LIBs) because of its high theoretical capacity, abundance, and low cost. However, Sn suffers from large volumetric expansion during charging and discharging causing cracking and degradation. Thus, development of new Sn based interfaces and architectures is crucial that can accommodate the volume changes and improve cyclic performance. In this study, we present the development of a novel Sn and hard carbon (hcarbon) architectures for LIB anodes, with a focus on improving their long-term stability and high capacity. The composite architectures are achieved through nano Physical Vapor Deposition (nano-PVD) technique by depositing Sn and hard carbon on copper substrate at the room temperature and a high temperature (470 oC). Our results show that the Sn and h-carbon architectures exhibit long-term cycling stability (> 79% capacity retention after 50 cycles) and higher capacities reaching upto 1570 mAh g-1 at 2nd cycle after SEI formation. The resultant microstructures especially at 400 oC created a multi-layer interface with Cu-Sn and h-carbon. The newly developed, so called soft (Cu-C-Sn) and a hard interface (h-Carbon) provides a cushion against volumetric expansion of Sn microstructures as shown in Figure 1. These findings demonstrate the potential of Sn and hard carbon as promising anode materials for advancing the performance of LIBs.