Researchers in South Korea have used an organogel binder—cyanoethyl polymer (PVA-CN)—to enhance the performance of silicon anodes for Li-ion batteries by utilizing the electroactivity of silicon in a more efficient way. A paper on their approach is published in the Journal of Power Sources. Members of the research team had earlier explored the use of PVA-CN as a high-ionic-conductivity (σi) electrolyte (Kimm et al. 2013).
Silicon, although a promising high-capacity anode material, suffers from volume expansion leading to pulverization and low conductivities, resulting in capacity decay during cycling and low capacities at fast charging and discharging.
Selectively accelerating Li+ transport through the organogel binder improved the kinetics of silicon lithiation while the strong cohesion/adhesion and optimized mechanical properties of the gel also supported durable cyclability.
The cyanoethyl polymer (PVA-CN), characterized by high lithium ion transference number as well as appropriate elastic modulus with strong adhesion, enhanced cycle stability of silicon anodes with high coulombic efficiency even at high temperature (60 °C) as well as at fast charging/discharging rates.—Hwang et al.
Chihyun Hwang, Yoon-Kyo Cho, Na-Ri Kang, Younghoon Ko, Ungju Lee, Dongjoon Ahn, Ju-Young Kim, Young-Jin Kim, Hyun-Kon Song (2015) “Selectively accelerated lithium ion transport to silicon anodes via an organogel binder” Journal of Power Sources, Volume 298, Pages 8-1 doi: 10.1016/j.jpowsour.2015.08.017
Young-Soo Kim, Yoon-Gyo Cho, Dorj Odkhuu, Noejung Park & Hyun-Kon Song (2013) “A physical organogel electrolyte: characterized by in situ thermo-irreversible gelation and single-ion-predominant conduction” Scientific Reports 3, Article number: 1917 doi: 10.1038/srep01917