Multibranched Polymer Solid Electrolyte for Battery Interface Resistance
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Solution Overview
Problem
All-solid-state secondary batteries face increased interface resistance due to hard solid electrolytes, which hinders ion conductivity and electrode flexibility, and existing polymer binders do not meet the required standards for high performance.
Innovation Solution
A solid electrolyte composition comprising an inorganic solid electrolyte and a multibranched polymer with a core and arm structure, where the arm portion contains specific repeating units and functional groups, is used to form a film on a metallic foil, reducing interface resistance and enhancing ion conductivity and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inorganic solid electrolyte is used, then reliability and incombustibility are improved, but interface resistance increases and ion conductivity decreases
Solution Approach 1:
The patent introduces a polymer binder as an intermediary substance between inorganic solid electrolyte particles. This binder fills the gaps and interfaces between hard solid particles, providing a softer matrix that reduces contact resistance and facilitates ion transport while maintaining the reliability benefits of inorganic electrolytes.
Solution Approach 2:
The patent creates a composite electrolyte system combining inorganic solid electrolyte particles with a polymer binder matrix. This composite structure leverages the high reliability and incombustibility of inorganic materials while the polymer component provides flexibility and reduced interface resistance, achieving a balance between contradictory properties.
2Reliability
If inorganic solid electrolyte is used, then incombustibility is improved, but electrode flexibility decreases
Solution Approach 1:
The patent applies different material properties to different regions of the electrolyte structure. The inorganic solid electrolyte particles provide localized incombustibility and structural integrity, while the polymer binder matrix provides localized flexibility and softness. This spatial differentiation of material properties allows the overall system to exhibit both incombustibility and flexibility.
Solution Approach 2:
By creating a composite structure where polymer binder surrounds and connects inorganic electrolyte particles, the material exhibits emergent properties that combine the rigidity and fire resistance of inorganic components with the flexibility of the polymer matrix, enabling electrodes to be both safe and flexible.
3Ease of manufacture
If conventional polymer binders are used, then ease of manufacture is improved, but performance (interface resistance reduction) is insufficient
Solution Approach 1:
The patent modifies key parameters of the polymer binder, specifically selecting polymers with glass transition temperatures of -50°C to 0°C and specific functional groups. These parameter changes optimize the polymer's softness and interfacial interaction properties, enabling effective reduction of interface resistance while maintaining ease of manufacturing through conventional processing methods.
Data Source
AI summary
A solid electrolyte composition includes an inorganic solid electrolyte having conductivity of metal ion belonging to Group 1 or 2 of the periodic table; and a multibranched polymer, in which the multibranched polymer is an amorphous polymer and includes a core portion and at least three polymeric arm portions that bond to the core portion.