A research team has developed a groundbreaking technology that could make lithium-ion batteries more stable and long-lasting under fast-charging conditions, a crucial step for the widespread adoption of electric vehicles (EVs).
Their findings were published in the journal Advanced Functional Materials.
For EVs to become more popular, their batteries need to offer longer driving ranges and be safe to use.
Fast charging is also essential for convenience.
However, increasing a battery’s energy density often requires thicker electrodes, which can degrade the battery during rapid charging.
To solve this problem, a team from the Korea Electrotechnology Research Institute (KERI) found a solution by coating the surface of the lithium-ion battery’s anode with tiny aluminum oxide (Al2O3) particles, each smaller than 1 micrometer.
While many researchers focus on the materials inside the electrode, Dr. Choi’s team used a simpler method to coat the electrode’s surface with aluminum oxide.
Aluminum oxide is inexpensive, has excellent electrical insulation, heat resistance, and chemical stability, and is widely used in ceramics.
The KERI researchers discovered that these particles help control the interface between the anode and the electrolyte in lithium-ion batteries.
This creates an efficient pathway for lithium ions (Li+) to move, preventing the electrodeposition of lithium during fast charging. This process ensures the stability and longevity of the battery.
This new technology also increases the energy density of lithium-ion batteries.
Introducing other materials into the electrode to improve performance can complicate the process and reduce the amount of reversible lithium, which can worsen performance during fast charging.
However, the KERI team’s method treats the surface of the graphite anode, avoiding changes to the internal graphite materials. This approach maintains stable performance even with high-energy-density thick-film electrodes during fast charging.
Tests confirmed that the high-energy-density anode coated with aluminum oxide (4.4 mAh/cm2) performs exceptionally well, retaining over 83.4% of its capacity even after 500 rapid charging cycles.
The team verified this performance with pouch cells of up to 500mAh and is now working to scale up the technology for larger battery cells.
The research was led by Dr. Choi Jeong Hee at KERI’s Battery Materials and Process Research Center, with collaboration from teams at Hanyang University and Kyunghee University.
Dr. Choi highlighted that this work could help develop stable, high-energy-density lithium-ion batteries capable of fast charging, aiding in the wider adoption of EVs and supporting national carbon neutrality goals.
Patents for this technology have been registered in both Korea and the United States.
Source: KSR.
