Research team at Chungnam National University in South Korea has successfully developed a novel electrolyte additive for pure silicon anode that is stably operated under ambient pressure. This breakthrough holds significant expectations for using pure Si anode (i.e., without graphite) in lithium-ion battery technologies.
In a recent publication in the Journal of Energy Chemistry, the team led by Professor Seung-Wan Song detailed their breakthrough. By using diacetoxydimethylsilane (DAMS) as an additive with highly loaded (3.5 mA h cm-2) pure Si-Fe anodes, they achieved unprecedented stable performance. When combined with 9 wt% FEC additives under ambient pressure, the use of 2 wt% DAMS additive showed promising results yielding high capacity of 1270 mA h g-1 at 0.5 C, along with an improved capacity retention rate of 81% after 100 cycles. This is in contrast to issues observed with FEC-only additives, including short circuits and rapid capacity decay.
The core of their innovation lies in addressing the critical issues associated with silicon anodes such as severe swelling and interfacial instability to the liquid electrolyte. Through their design strategies of novel carboxy silane additive and inorganics (e.g., siloxanes)-enriched robust and uniform solid electrolyte interphase (SEI) (i.e., surface protective layer) construction, the team succeeded in suppressing the swelling phenomenon and ensuring the stable performance of high-capacity pure Si anode.
This accomplishment holds a potential to contribute to the realization and commercialization of pure Si anodes and next-generation high-energy density Li-ion batteries.
Seung-Wan Song
This work was supported by National Research Foundation grant funded by the Ministry of Science and ICT of Korea (No. 2021M3H4A3A02086211 and No. RS-2023-00217581).