Borylated Polymer Electrolytes for High-Conductivity Solid-State Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid-state polymer electrolytes exhibit low conductivity and lithium transference number (tLi+) due to the immobility of lithium cations in the polymer matrix, particularly at lower temperatures, and previous modifications such as incorporating Lewis acidic sites have not significantly improved conductivity without compromising the polymer's mechanical properties.
Innovation Solution
Development of polyolefin-based solid-state polymer electrolytes through the hydroboration of polybutadiene to introduce boron-based groups in the side chain, creating a polymer with high boron concentration and a rigid backbone, which enhances ion conductivity and tLi+ without coordinating heteroatoms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solid-state polymer electrolytes are used to replace liquid electrolytes for safety improvement, then safety is improved, but conductivity and lithium transference number decrease
Solution Approach 1:
The patent changes the chemical composition parameters of the polymer electrolyte by incorporating boron-containing groups with high Lewis acidity into the polymer backbone. This parameter change increases the lithium transference number from typical low values to above 0.5, while maintaining solid-state safety advantages. The boron groups create stronger ion-dipole interactions that enhance lithium ion mobility without requiring liquid solvents.
Solution Approach 2:
The patent creates a composite polymer electrolyte system combining polyethylene oxide chains with boron-containing functional groups (such as boroxine rings or boronic ester groups). This composite structure integrates the mechanical flexibility of PEO with the high lithium transference number characteristics of boron-based Lewis acidic sites, achieving both safety and improved ionic conductivity.
2Quantity of substance
If polymer electrolyte composition is modified to improve conductivity, then conductivity is improved, but mechanical properties deteriorate
Solution Approach 1:
The patent modifies the polymer electrolyte by changing the chemical structure parameters to include rigid boron-containing cyclic groups (boroxine or boronic ester) in the backbone. These structural changes enhance mechanical strength through increased chain stiffness and intermolecular interactions, while the Lewis acidic boron sites simultaneously improve ionic conductivity through enhanced lithium ion coordination.
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 new polymer electrolytes demonstrate high ion conductivity and tLi+ across various temperatures, with tunable conductivity based on composition, and improved mechanical properties compared to previous electrolytes.
Implementation Method 1
Lewis acidic sites are incorporated into solid-state polymer electrolytes as anion receptors to enhance their ionic conductivity and/or tLi+. In these systems, the interaction between the anions and the Lewis acidic site promotes the dissociation of lithium cation
Implementation Method 2
polyolefin-based solid-state polymer electrolytes prepared by the simple hydroboration of polybutadiene resulting in a saturated or unsaturated carbon backbone bearing boron-based groups in the side chain
Data Source
AI summary
The present disclosure provides solid-state electrolytes based on a borylated-polymers (e.g., borylated-polybutadiene). Further provided are kits comprising, methods of synthesizing, and methods of using the solid-state electrolytes. In some aspects, the solid-state electrolytes demonstrate high ion conductivity at room temperature.