Designing Polymer Electrolytes via Ring‐Opening Polymerization for Advanced Lithium Batteries

Abstract

Replacing liquid electrolytes with solid‐state polymer electrolytes (SPEs) can solve the safety hazards of Li metal batteries (LMBs) while increasing their energy density. However, there has been limited success so far in preparing advanced SPEs with controllable molecular structure and chemical composition, posing great obstacles to further promoting its application in LMBs. Recently, ring‐opening polymerization (ROP), including cationic ROP, anionic ROP, and ring‐opening metathesis polymerization, has become a dazzling new star in achieving SPEs due to its mild polymerization conditions and controllable chemical composition (molecular structure, functional group), etc. Besides, there is no small molecule released during the polymerization process, which means reduced interfacial side reaction. Hence, in this review, the merits of ROP in preparing SPEs and its mechanism as well as interfering factors, etc are evaluated from the perspective of synthetic chemistry. Furthermore, the review focuses on outlining the existing cases related to ROP as much as possible and summarize them from different ring structures (from triple ring to multivariate ring) and polymerization methods, hoping to provide a comprehensive understanding and serve as strategic guidance for designing high‐performance SPEs. Challenges and opportunities regarding this burgeoning field are also discussed at the end.

Polymer design for solid-state batteries and wearable electronics

“…The ROP of cyclic lactones, carbonates and epoxides is another choice for in situ polymerisation owing to their high efficiency and mild polymerisation conditions. 144 Often unfavourable entropically (Δ S < 0), ROP is driven by enthalpic contributions (Δ H < 0) related to the ring stain of the monomer ( Fig. 4b ).…”

In Situ Solid-State DETFPi-PDOL Electrolyte and Its Impact on the Interfaces and Performance of NCM811||Li Batteries

“…and cyclic monomers (1,3-dioxolane (DOL), ε-caprolactone (CL), etc. ). − Among them, DOL can form a polyether-structured poly-DOL (PDOL) electrolyte with good flexibility and stability to lithium anode through cationic ring opening polymerization . Guo and co-workers first reported PDOL quasi-solid-state electrolyte, prepared through in situ gelation of DOL/DME electrolyte solution induced by LiPF 6 and realized over 700 cycles of LiFePO 4 ||Li battery.…”

High Voltage and Cycling Stable Norbornene-Based Polycarbonate Electrolyte for Lithium Metal Battery

“…33 However, there are very few investigations into the mechanism of electrochemical applications. 33 In these studies, poly(norbornene)-based electrolytes prepared via the ROMP method exhibit potential for application in high-performance solid-state lithium batteries. First, poly(norbornene)-based polymer electrolytes exhibit good thermal stability, which is very suitable for high-temperature lithium batteries.…”

“…Ring-opening metathesis polymerization (ROMP) is a widely applied and powerful method to synthesize diverse polymers with a wide range of properties, functionalities, and architectures under mild conditions from cyclic olefins. , Polymer electrolytes prepared via ROMP have raised much attention in recent years (Table S2). − The majority of research efforts are focused on the synthesis of the molecules and exploration of the fundamental electrochemical properties . However, there are very few investigations into the mechanism of electrochemical applications .…”

“…The assembled batteries presented superior electrochemical performance. Last, but not least, the ROMP of the norbornene derivative can be employed to construct higher-order structure in SPEs through block, graft, and hyperbranched copolymers. , Thelakkat synthesized a bottlebrush polynorbornene carrying PEG side chains. Compared to linear PEG, the bottlebrush polymer electrolyte exhibits an ionic conductivity 1 order of magnitude higher at 25–80 °C.…”