**- KERI Develops New Anode Material ‘Tin-Iron Compound’**
– Achieves Higher Capacity and Stability Compared to Existing Materials
[Herald Economy = Bonhyuk Koo] The Korea Electrotechnology Research Institute (KERI), in collaboration with Kumoh National Institute of Technology and Inha University, has conducted research on anode materials for all-solid-state batteries. The results of this study have been published as a cover paper in a leading journal in the energy field.
All-solid-state batteries replace the liquid electrolyte between the anode and cathode, which poses a risk of fire or explosion, with a solid that has significantly lower risks. However, the nature of solid components requires advanced technology to ensure stability during charge and discharge cycles. The material used for the anode is particularly crucial as it significantly impacts the charging speed and lifespan of the battery.
Currently, lithium metal is the most researched anode material for all-solid-state batteries. However, repeated charging and discharging lead to the growth of dendrites resembling tree branches on the lithium surface, causing internal short circuits and threatening the battery’s lifespan and stability. Silicon anodes are an alternative but suffer from low electronic and ionic conductivity and cracking due to volume expansion.
The joint research team has introduced a tin (Sn)-based alloy ‘tin-iron compound (FeSn2)’ as the anode material. Through detailed mechanical analysis, the team found that FeSn2 has a re-combination reaction that reduces particle size during repeated charging and discharging. This ensures prolonged contact among solid particles within the all-solid-state battery, forming dense, uniform electrodes. Even under external stress, FeSn2 maintains high elasticity and deformation energy, ensuring excellent electrochemical stability without cracking.
For validation, the research team created a test ‘full cell’ with a FeSn2 anode, an NCM622 cathode (a combination of nickel, cobalt, and manganese), and a sulfide solid electrolyte (Li6PS5C1). The resultant battery achieved a ‘capacity per area’ five times higher than traditional lithium-ion batteries. Additionally, over 1000 rapid charge-discharge cycles were conducted in 3-minute and 6-minute intervals, with the battery retaining more than 70-80% of its capacity.
Furthermore, the research team applied the FeSn2 anode to a pouch cell prototype to assess performance, achieving an energy density exceeding 255 Wh/kg, demonstrating commercial potential.
Hyun Chul Ha, the Director of the Next-Generation Battery Research Center, stated, “This achievement is significant because it breaks away from the traditional focus on lithium metal and silicon anode research in all-solid-state batteries, demonstrating the great potential of tin-based alloy anodes.”
The results have gained recognition for their excellence and have been published as the cover paper of the October issue of ‘Joule,’ an international academic journal ranked in the top 1% according to the Journal Citation Reports (JCR).