Crosslinked PEO Polymer Electrolyte for Dendrite-Resistant Li Metal Batteries
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Solution Overview
Problem
Conventional solid-state polymer electrolytes for lithium batteries face challenges such as low ionic conductivity, high electrode resistance, and non-uniform lithium deposition due to strong interactions between lithium ions and polymer chains, leading to energy loss and safety concerns.
Innovation Solution
The development of an interpenetrating polymer network electrolyte (IPNE) using a modified poly(ethylene oxide)-based polymer with epoxy alkane crosslinkers like polyhedral oligomeric silsesquioxane (POSS) and poly(vinylidene fluoride)-based networks, which enhances ion transport and mechanical strength, and incorporates lithium bis(fluorosulfonyl)imide (LiFSI) to facilitate uniform lithium distribution and reduce space charge accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Li-metal anodes are used to achieve high energy density, then battery capacity is improved, but dendrite formation and safety risks increase
Solution Approach 1:
The patent modifies the electrolyte's physical and chemical parameters by incorporating POSS crosslinkers, which alter the network's polarity, mechanical properties, and ion transport characteristics. These parameter changes create conditions that favor uniform Li+ deposition and suppress dendrite formation while maintaining high capacity
Solution Approach 2:
The POSS-containing polymer network acts as an intermediary layer between the Li-metal anode and the bulk electrolyte. This intermediate structure provides a controlled interface that guides uniform Li+ deposition, preventing direct contact between the aggressive Li metal and the bulk electrolyte that would otherwise promote dendrite growth
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
The IPNE achieves high ionic conductivity (approximately 1 mS cm−1) and a high lithium transference number (0.7) at 30°C, enabling superior charge-discharge performance and preventing lithium dendrite formation, thus improving the safety and efficiency of lithium metal batteries.
Implementation Method 1
the Li+-transference number (tLi+) of ion conduction in SPEs
Implementation Method 2
strong attraction of high-polarity polymer chains to Li+
Implementation Method 3
epoxy alkane crosslinkers, such as polyhedral oligomeric silsesquioxane (POSS) to produce a polymeric network
Implementation Method 4
incorporates lithium bis(fluorosulfonyl)imide (LiFSI) to facilitate uniform lithium distribution
Implementation Method 5
FSI− may aggregate to form a polymer-like ionic network capable of facilitating the migration of Li+
Implementation Method 6
interpenetrating polymer network electrolyte (IPNE) including incorporated polymer networks possessing enhanced ion-complex dissociating and Li+ transport regulating abilities
Data Source
AI summary
A solid-state polymer electrolyte for lithium batteries is provided. The solid-state polymer electrolyte includes a solid-state network polymer electrolyte, formed by a modified poly(ethylene oxide) polymer material and an epoxy alkane crosslinking agent to form a poly(ethylene oxide) network structure, wherein the modified poly(ethylene oxide) high molecular weight material has an amino end, and the solid-state network polymer electrolyte comprises a lithium salt, The ratio of ethylene oxide (EO) to lithium (Li) in the solid-state network polymer electrolyte is 1:1 to 3:1, and a poly(vinylidene fluoride)-based polymer is doped in the solid-state network polymer electrolyte.