New class of single-ion-conducting solid polymer electrolytes derived from polyphenols

Solid polymer electrolytes (SPEs) continue to be the subject of intense research due to their potential applications in rechargeable lithium batteries, specific ion sensors, electrochromic displays, and other electrochemical devices. However, the optimization of key parameters such as ionic conductivity, mechanical strength, and electrochemical stability is necessary for SPEs to be suitable for practical lithium batteries. Single-ion conductors have advantages over typical biion-based SPEs. During discharge in biion salt-based SPEs, mobile anions and cations migrate toward the oppositely charged electrodes, thereby polarizing the electrolyte and increasing its resistivity. Recharging the cell then requires more energy, time, and a greater electrochemical potential. This cell polarization problem is unique to biionic salt-based SPEs. This problem can be solved by using single-ion based conductors in which the anions are immobilized. In this communication, the authors report preliminary studies utilizing lithium polyphenolates as a new class of lithium ion source, which when blended with high molecular weight poly(ethylene oxide) give a new type of SPEs that exhibit high ionic conductivities.