A team has created a reliable and efficient polymer-based solid electrolyte suitable for smartphones, electric vehicles, and energy storage.
Researchers from DGIST’s Energy & Environmental Technology Division, led by Principal Researcher Kim Jae-hyun, have made significant strides by developing a lithium metal battery featuring a “triple-layer solid polymer electrolyte.” This innovative design greatly improves fire safety and extends the battery’s lifespan. The findings from this research are relevant for various uses, including in electric vehicles and extensive energy storage solutions.
Traditional solid polymer electrolyte batteries often struggle because of structural constraints that limit effective contact with the electrodes. Additionally, these batteries have not resolved the “dendrite” issue, where lithium forms tree-like structures during charging and discharging cycles. Dendrites pose a serious problem, as their irregular growth can disrupt connections within the battery, potentially leading to fires or explosions.
To tackle these challenges, the research team designed a triple-layer structure for the electrolyte. Each layer serves a specific purpose, significantly improving both safety and performance. This advanced electrolyte uses “decabromodiphenyl ethane (DBDPE)” to enhance fire resistance, “zeolite” to increase the electrolyte’s strength, and a high concentration of lithium salt, “lithium bis (trifluoromethanesulfonyl) imide (LiTFSI),” to ensure quick movement of lithium ions.
The triple-layer electrolyte includes a strong middle layer that enhances mechanical strength, while the softer outer layer ensures excellent electrode contact, which allows for easy movement of lithium ions. This design not only expedites lithium ion movement but also mitigates dendrite formation effectively, thereby improving energy transfer rates.
Experimental results indicated that the newly developed battery maintained about 87.9% of its performance after 1,000 charge and discharge cycles, a significant increase in durability compared to conventional batteries that usually retain only 70-80%. Additionally, the battery can extinguish itself during a fire, greatly lowering the risk of fire hazards. This battery is anticipated to be used in various applications, from small gadgets like smartphones and wearable tech to electric vehicles and large energy storage systems.
Dr. Kim remarked, “We anticipate that this research will greatly contribute to the commercial viability of lithium metal batteries utilizing [solid polymer] electrolytes, while enhancing the stability and efficiency of energy storage devices.”
This research was backed by the Future Materials Discovery Project, led by Professor Lee Jung-ho from Hanyang University, along with the Mid-Career Researcher Program, overseen by Dr. Kim Jae-hyun, from the National Research Foundation of Korea. The results were featured as the cover article in the international journal Small, published by Wiley.
