Comb-Chain Crosslinked Solid Polymer Electrolytes for Dendrite Resistance

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Solution Overview

Problem

Lithium metal batteries face challenges with lithium dendrite growth and resistance due to limited physical chain entanglements in existing solid polymer electrolytes, particularly at high current densities, which hinders their practical application.

Innovation Solution

The development of comb-chain crosslinked network solid polymer electrolytes (ConSPEs) formed by reacting poly(glycidyl methacrylate) with functionalized poly(ethylene glycol) or poly(ethylene oxide) in the presence of lithium salts, creating a robust and flexible network with enhanced lithium dendrite resistance and mechanical toughness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If classical main-chain, side-chain, or block copolymer SPEs are used, then mechanical properties and ionic conductivity can be tuned, but lithium dendrite resistance is poor due to limited physical chain entanglements and susceptibility to plastic deformation

Engineering Contradiction:

Improvelithium dendrite resistanceVSAvoidmechanical strength

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent combines physical chain entanglements with chemical crosslinking to create a composite network structure. The comb-chain architecture integrates PEO side chains (for ionic conductivity) with a crosslinked backbone (for mechanical strength), achieving both dendrite resistance and structural integrity simultaneously.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent pre-forms polymers with controlled viscosity and uniform network structure before final assembly. The comb-chain architecture is designed in advance with specific PEO side chain lengths and crosslinking densities to ensure optimal mechanical properties and ionic conductivity before battery assembly.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If network SPEs with chemical crosslinking are used, then lithium dendrite resistance is improved, but the network becomes relatively rigid with small molecular mesh size, reducing deformability

Engineering Contradiction:

Improvelithium dendrite resistanceVSAvoiddeformability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent creates local PEO-rich domains within the comb-chain structure that provide ionic conductivity and flexibility, while the crosslinked backbone provides overall structural support. This local differentiation allows the material to be rigid where needed and flexible where needed for ion transport.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent adjusts the molecular weight of PEO side chains and the density of crosslinking points to optimize the balance between rigidity and deformability. By controlling these parameters, the network maintains structural integrity while allowing sufficient chain mobility for ion transport and adaptation to electrode volume changes.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If small crosslinked domains are grown and merged to form network SPEs, then chemical crosslinking is achieved, but heterogeneity arises and the network becomes relatively rigid

Engineering Contradiction:

Improvechemical crosslinkingVSAvoidnetwork homogeneity

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent pre-forms the PEO side chains with controlled molecular weights before crosslinking, ensuring uniform distribution throughout the polymer matrix. This preliminary organization of chains prevents random aggregation and promotes homogeneous crosslinking throughout the network structure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses comb-chain architecture where identical PEO side chains are attached at regular intervals along the backbone, creating a uniform structure that crosslinks homogeneously. This regular spacing and uniform chain architecture eliminate the heterogeneity that arises from random crosslinking of small domains.

Inventive Principle:

Principle #33Homogeneity

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

ConSPEs demonstrate improved lithium dendrite resistance, anodic stability, and battery performance, enabling stable cycling up to 10 C rate and maintaining performance over a wide temperature range, making them suitable for high-performance and dendrite-free lithium metal batteries.

Implementation Method 1

solid polymer electrolyte including a comb-chain crosslinked network formed by reacting poly(glycidyl methacrylate) with a functionalized poly(ethylene glycol) or functionalized poly(ethylene oxide) in the presence of one or more lithium salts

Methodology Applied

Scientific EffectIon conduction: Conduction (electrical)

Data Source

PatentUS20230246231A1Solid polymer electrolytes for solid-state lithium metal batteries

Publication Date: 2023.08.03 DREXEL UNIV

AI summary

A solid polymer electrolyte including a comb-chain crosslinked network formed by reacting poly(glycidyl methacrylate) with a functionalized poly(ethylene glycol) or functionalized poly(ethylene oxide). Batteries including the solid polymer electrolytes, a cathode, and a metal anode or one or more lithium salts are also described. A process of preparing the solid polymer electrolyte involves reacting a poly(glycidyl methacrylate) with a functionalized poly(ethylene glycol) or functionalized poly(ethylene oxide) to form a crosslinked network in a single-step polymerization process. The solid polymer electrolyte provides improved resistance to lithium dendrite formation and has excellent physical and electrical properties that make it particularly suitable for use in lithium batteries.