Synthesis of Conducting Polymer-Intercalated Vanadate Nanofiber Composites utilizing Sonochemistry and Their Applications as Dynamically Stretchable Zinc-Ion Micro-Batteries Operating in Extreme Environments
The Korean Electrochemical society, YEOSU EXPO, Korea(2023)
Se Hun Lee, Ok Sung Jeon, Dong Pyo Hong, Yong Yeol Park, Seo Young Kang, Yong Joon Lee, Jae Yeon Won, Heejoon Ahn, Young Joon Yoo, Sang Yoon Park
Abstract
This study revolves around the development and use of stretchable zinc-ion micro-batteries (SZIMBs), crucial for wearable device applications. Many researchers have proposed various designs for SZIMBs, but their mechanical performance often suffers due to the lack of flexibility in the active materials of the electrodes. This research introduces a poly(3,4-ethylene dioxythiophene) (PEDOT)-intercalated zinc vanadium oxide nanofiber composite (E-ZVONF) as a cathode material for SZIMBs, synthesized through a simple sonochemical method. This new E-ZVONF composite brings flexibility and elasticity to the ceramic material and stabilizes the charge/discharge process. In addition, a new method called "short nduced pre-zincation (SIPZ)" is also introduced to improve the electrode thickness-dependence issue in stretchable devices field. The SIPZ method simplifies pre-zincation by adding zinc metal powder to the cathode, providing a more efficient approach compared to existing techniques. This research also proposes a wave-type SZIMB assembly that shows excellent electrochemical performance even when the thickness of the zinc metal anode is significantly reduced. When combined with the E-ZVONF composite, SIPZ method, and wave-type assembly, the new SZIMB demonstrated superior capacity retention under stretching conditions. By integrating these strategies, the fabricated PEDOT-intercalated zinc vanadium oxide nanofiber zinc-ion micro-batteries (E-ZVONF-SZIMBs) exhibit a peak specific capacity of 0.16 mAh cm-2, a high energy density of 0.112 mWh cm-2, a substantial power density of 3.5 mW cm-2, and they retain 83.7% of the initial specific capacity after 500 cycles. Further, the E-ZVONF-SZIMBs preserve 78.9% of the initial specific capacity even post 7,000 mechanical stretching/bending cycles, thereby demonstrating exceptional operando dynamic stretchability. Notably, they display practical viability by sustaining 80% and 90% of the capacity at -20 °C and 60 °C under 200% strain, respectively. These outstanding accomplishments in the realm of stretchable zinc-ion micro-batteries are anticipated to be impactful for the progression of future device platforms.