Great Challenges and New Paradigm of The In Situ Polymerization Technology Inside Lithium Batteries

Abstract

In situ polymerization technology is expected to empower the next generation high specific energy lithium batteries with high safety and excellent cycling performance. Nevertheless, the large‐scale commercial applications of most reported in situ polymer electrolytes are still full of challenges. Owing to the severe parasitic reactions caused by residual monomers, additional initiators and oligomers, lithium batteries using in situ polymer electrolytes often demonstrate limited specific capacity, poor cycling performance, and insufficient rate capability. However, this issue has not received adequate attention in previous reports. Furthermore, the design and evaluation of in situ polymer electrolytes still lack effective guidance and unified standards. Herein, the development history of in situ polymer electrolytes are systematically reviewed and critically disclose the great challenges. Then, from the aspects of monomers, initiators, separators, manufacturing technologies, safety and cycle life evaluation, unprecedentedly a new paradigm is provided for upgrading the in situ polymerization technology inside lithium batteries. It is hoped the novel paradigm will prompt much more insightful studies, expediting the commercialization of in situ polymerization technology in lithium batteries.

A composite electrolyte based on aluminum oxide filler/polyester polymer via in situ thermal polymerization for long-cycle sodium metal batteries

“…5–7 Consequently, it is crucial to focus on establishing a stable interface and enhancing ionic conductivity at room temperature. 8 GPEs have gained significant attention due to their ability to confine the precursor solution to the polymer matrix through in situ polymerization, which can enhance the continuous contact between the electrolyte and the electrode, and minimize the risk of electrolyte leakage. 9–11 However, the mechanical strength of the GPEs is not strong enough to inhibit the growth of sodium dendrite, which will eventually lead to discontinuous interfacial contact and continuous cracking/repair of the solid electrolyte interface (SEI).…”

In Situ Integration of a Flame Retardant Quasisolid Gel Polymer Electrolyte with a Si-Based Anode for High-Energy Li-Ion Batteries

“…In situ polymerization and solidification of monomercontaining precursor solutions in cells could greatly improve the solid/solid interface contact, especially for powder electrodes, where the precursor solutions can permeate the electrode pores to create an integrated structure. 33 Various polymer monomers, such as VC, 34 vinylethylene carbonate (VEC), 35 methacrylate (MMA), 36 ethoxylated trimethylolpropanetriacrylate (ETPTA), 35 1,3-dioxolane (DOL), 37 and lithium perfluoropinacolatoaluminate (LiFPA), 38 are currently employed for the in situ polymerization. However, the abovementioned monomers face challenges in achieving a balance between rigidity and flexibility to ensure the synchronous expansion and contraction following the Si volume change during cycling.…”

Hierarchical Carbon Interlayer Design as Interfacial Stabilizer and In-Situ Solid-Electrolyte Infiltrate for High-Performance Solid-State Li–S Batteries

“…In order to address these problems aformentioned, the design of solid-state Li–S batteries that can sustain the ability to retard the dissolution of LiPSs and simultaneously inhibit the growth of lithium dendrites is spotlighted . − In this regard, gel polymer electrolytes (GPEs) are composed of a unique hybrid network structure enabling both the cohesion of solid polymer electrolytes (SPEs) and the diffusivity of liquid electrolytes. − This feature benefits to balance the mechanical and electrochemical properties of the overall cell performance. − However, traditional manufacturing of GPEs refers to an ex-situ polymerization process, that is, an independent polymer electrolyte film is pre-prepared before cell assembly and thereafter stack-by-stack assembled between electrodes into the battery. − However, sulfur cathodes that are mostly applied in Li–S batteries are based on porous carbon matrix for the sake of better sulfur utilization and ionic/electron conductivities. Ex-situ prepared GPEs fail to provide sufficient contact within positive electrodes, greatly sacrificing the utilization of active substances and the achievable energy density.…”