A research team at the Korea Electrotechnology Research Institute (KERI) Battery Materials and Process Research Center, in collaboration with a Hanyang University team and a Kyunghee University team, has developed a core technology to ensure the charging/discharging stability and long-life of lithium-ion batteries under fast-charging conditions.
Improving the performance of lithium-ion batteries in terms of driving range and safety is essential to accelerating the widespread adoption of electric vehicles (EVs). Fast charging is also crucial for user convenience.
However, the challenge lies in increasing the energy density of lithium-ion batteries, as this often requires thicker electrodes. This can lead to battery degradation and reduced performance during rapid charging.
To tackle this challenge, the KERI team has devised a groundbreaking solution: they have partially coated the surface of the lithium-ion battery‘s anode with aluminum oxide (Al2O3) particles smaller than 1 micrometer (㎛).
While many researchers around the world have focused on enhancing the materials within the electrode, such as incorporating advanced nanotechnology into anode materials like graphite, Dr. Choi’s team has implemented a simple yet effective technique to apply a layer of aluminum oxide to the electrode’s surface.
Aluminum oxide is a cost-effective, highly insulating, and heat-resistant material with excellent chemical stability and mechanical properties. Researchers at KERI have discovered that aluminum oxide particles play a crucial role in enhancing the performance and lifespan of lithium-ion batteries.
By effectively managing the interface between the anode and the electrolyte, these particles create an efficient pathway for lithium ion transport. This mechanism prevents the unwanted electrodeposition of lithium during rapid charging, thereby ensuring the battery’s stability and longevity during charge and discharge cycles.
This technology offers the advantage of increasing the energy density of lithium-ion batteries. Unlike methods that introduce additional materials into the electrode’s interior, which can complicate the synthesis process and reduce the amount of reversible lithium, the KERI technology focuses on surface treatment of the graphite anode.
By treating the graphite anode’s surface instead of modifying the interior materials, the team achieves stable performance for high-energy-density thick-film electrodes under fast charging conditions without a loss in the amount of reversible lithium.
Through testing, the team confirmed that the high-energy-density anode coated with aluminum oxide exhibits world-class performance, maintaining over 83.4% of its capacity even after 500 cycles of rapid charging. This technology shows promise for scaling up to large-capacity cells.
“Convenient, fast charging and the energy density of lithium-ion batteries have long been considered a trade-off, which has hindered the widespread adoption of electric vehicles,” said lead researchers Dr. Choi Jeong Hee from KERI Battery Materials and Process Research Center. “Our work will help develop stable, high-energy-density lithium-ion batteries capable of fast charging. This advancement will contribute to the wider adoption of EVs and support the achievement of national carbon neutrality.”
Journal reference:
- Jeong-Hee Choi, Hae Gon Lee, Min-Ho Lee, Sang-Min Lee, Junhee Kang, Joo Hyeong Suh, Min-Sik Park, Jong-Won Lee. Multi-Interface Strategy for Electrode Tailoring Toward Fast-Charging Lithium-Ion Batteries. Advanced Functional Materials, 2024; DOI: 10.1002/adfm.202400414