Safety-enhanced Polymer Electrolytes with High Ambient-temperature Lithium-ion Conductivity Based on ABA Triblock Copolymers

Abstract

Liquid electrolytes used in lithium-ion batteries suffer from leakage, flammability, and lithium dendrites, making polymer electrolyte a potential alternative. Herein, a series of ABA triblock copolymers (ABA-x) containing a mesogen-jacketed liquid crystalline polymer (MJLCP) with a polynorbornene backbone as segment A and a second polynorbornene-based polymer having poly(ethylene oxide) (PEO) side chains as segment B were synthesized through tandem ring-opening metathesis polymerizations. The block copolymers can self-assemble into ordered morphologies at 200 °C. After doping of lithium salts and ionic liquid (IL), ABA-x self-assembles into cylindrical structures. The MJLCP segments with a high glass transition temperature and a stable liquid crystalline phase serve as physical crosslinking points, which significantly improve the mechanical performance of the polymer electrolytes. The ionic conductivity of ABA-x/lithium salt/IL is as high as 10 −3 S•cm −1 at ambient temperature owing to the high IL uptake and the continuous phase of conducting PEO domains. The relationship between ionic conductivity and temperature fits the Vogel-Tamman-Fulcher (VTF) equation. In addition, the electrolyte films are flame retardant owing to the addition of IL. The polymer electrolytes with good safety and high ambient-temperature ionic conductivity developed in this work are potentially useful in solid lithium-ion batteries.

Theoretical Derivation of the Effect of Bonding Current on the Bonding Interface during Anodic Bonding of PEG-Based Encapsulation Materials and Aluminum

“…That is, if the bonding temperature is increased, the reaction to the electrical parameters is the decrease in R 1 . However, the bonding temperature may not be increased to reduce the bulk resistance blindly because the increase in temperature can cause the material to soften, preventing bonding [ 39 , 40 ].…”

Liquid Crystalline Nanoparticles via Polymerization‐Induced Self‐Assembly: Morphology Evolution and Function Regulation

“…[70] There have been studies using tandem ring-opening metathesis polymerization (ROMP) to prepare mesogen-jacketed LC BCPs. [71] In the recent reverse sequence PISA method, the LC blocks, which are usually used as solvophobic blocks, may polymerize before the solvophilic blocks. [72] This counter-intuitive approach may also expand the preparation mode of PISA-LC NPs.…”

“…Ring‐opening metathesis polymerization‐induced self‐assembly (ROMPISA) is a non‐radical PISA method, which has strong monomer tolerance and unique advantages in the preparation of multi‐block copolymers [70] . There have been studies using tandem ring‐opening metathesis polymerization (ROMP) to prepare mesogen‐jacketed LC BCPs [71] . In the recent reverse sequence PISA method, the LC blocks, which are usually used as solvophobic blocks, may polymerize before the solvophilic blocks [72] .…”

Enhancing ionic conductivity in tablet–bottlebrush block copolymer electrolytes with well-aligned nanostructures via solvent vapor annealing

“…6 For a diblock copolymer, the domain (e.g., polyethylene oxide (PEO)) with the capability of ion transport is called the conducting domain, and the other domain that mainly maintains the mechanical strength and high-temperature stability is called the supporting domain. [7][8][9] Generally speaking, there are four common thermodynamically stable microphase-separated morphologies for diblock copolymers including spheres (S), cylinders (HEX), lamellae (LAM), and double gyroids (G). 3,10,11 The ionic conductivity of the BCPE (s b ) is considered to be correlated with the intrinsic ionic conductivity of PEO (s E ), the volume fraction of PEO ( f PEO ), and the morphology factor ( f ).…”