Unmet Need: High cycling rates of tin nanoneedles films on Li-ion battery anode
During tin nanoneedle deposition of negative electrodes in Li-ion batteries, an interfacial solid tin layer forms between the copper current collector and the outer tin nanoneedles. This interfacial layer causes the overall electrode performance to mimic that of a thick tin film – rapid capacity fade with macro-scale cracking/pulverization of the electrode. Reducing the interfacial thickness improves cycling stability but not as required.
The Technology: Using Li-Sn alloy to improve cycling stability
The proposed method to further improve the cycling stability significantly is coupling with Li-Sn alloy phase control. The combination results in improved cycling of tin nanoneedle films from 15 cycles to >60 cycles with the tradeoff of lower overall electrode capacity due to selective Li-Sn alloy formation. Li-Sn alloy phase control through electrode potential can avoid or minimize the large density transition observed between LiSn and Li2.33Sn, and opens the possibility of improved cycling stability in other tin films.
• Better performance Lithium ion batteries.
• Power backup devices, UPS, electric vehicles.
• Solar power storage, remote surveillance systems.
• Cycling stability increases by 200%.
• Eliminates cracking and pulverization.
• Less degradation of tin films.