Composite Solid-State Electrolyte for Dendrite-Resistant Lithium Batteries
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Solution Overview
Problem
Current lithium-ion batteries face limitations in energy density, charging speed, and safety due to graphite anodes and liquid electrolytes, which are inefficient and pose fire risks, prompting the need for solid-state batteries with improved anode materials and electrolytes.
Innovation Solution
The development of a hybrid composite solid electrolyte (CSE) composed of polymers, lithium salts, solvent plasticizers, and inorganic additives, which can be processed as a liquid slurry and applied to substrates, including electrodes and separators, to form a freestanding separator film or laminate, enhancing ion transport and mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid electrolytes are used in lithium-ion batteries, then ion transport is facilitated, but fire safety risks increase due to volatility and flammability
Solution Approach 1:
The patent changes the physical state of the electrolyte from liquid to solid by incorporating polymer matrices and inorganic fillers, fundamentally altering the safety parameters while maintaining ionic conductivity. The solid-state electrolyte composition eliminates volatility and flammability inherent in liquid electrolytes.
Solution Approach 2:
The patent employs composite materials combining polymer matrices (such as polyethylene oxide, polyacrylonitrile) with inorganic fillers (such as alumina, silica, titania) to create a solid-state electrolyte that兼具 ionic conductivity and thermal stability, resolving the contradiction between safety and performance.
2Reliability
If graphite anodes are used, then coulombic efficiency is high, but specific capacity is limited to approximately 370 mAh/g
Solution Approach 1:
The patent changes the anode material from graphite to lithium metal, fundamentally altering the capacity parameter. Lithium metal provides theoretical specific capacity exceeding 3860 mAh/g, dramatically increasing the quantity of lithium that can be stored while the solid-state electrolyte enables this transition by preventing dendrite formation.
3Reliability
If solid-state electrolytes are used, then safety and thermal stability improve, but manufacturing complexity increases due to processing requirements
Solution Approach 1:
The patent modifies the processing parameters by incorporating solvent plasticizers that enable the solid-state electrolyte to be applied as a liquid slurry at lower temperatures, then removed through evaporation or extraction, simplifying the manufacturing process while maintaining thermal stability.
Solution Approach 2:
The patent uses solvent plasticizers as intermediary substances that facilitate processing. These solvents allow the electrolyte components to be mixed and applied in liquid form, then are removed to leave the final solid-state product, acting as a temporary mediator that simplifies manufacturing.
4Temperature
If inorganic fillers are added to polymer electrolytes, then thermal stability improves, but ion conductivity may be reduced due to increased viscosity
Solution Approach 1:
The patent optimizes the size, shape, and surface treatment of inorganic filler particles to minimize their impact on polymer chain mobility. By controlling filler morphology and surface properties, the patent maintains low viscosity and high ion conductivity while achieving superior thermal stability.
Solution Approach 2:
The patent employs porous inorganic fillers with controlled pore structures that provide pathways for ion transport while maintaining thermal stability. The porous structure reduces the effective volume fraction of filler, minimizing viscosity increase while preserving ionic conductivity channels.
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 CSE improves lithium-ion battery performance by increasing energy density, charging speed, and safety by providing a stable, ionically conductive yet electronically insulative barrier that prevents short-circuits and dendrite growth, while being more thermally stable than traditional liquid electrolytes.
Implementation Method 1
a separator that is free-standing and comprised of a composite solid-state electrolyte... providing a stable, ionically conductive yet electronically insulative barrier
Implementation Method 2
The addition of solvent plasticizers allows the CSE to be processed in a liquid slurry form
Implementation Method 3
inactive (not intrinsically Li-ion conductive) inorganic additive particles... continuous or discontinuous reinforcement phases
Implementation Method 4
lithium salts... that facilitates the transfer of lithium between the electrodes
Data Source
AI summary
The disclosure relates to a composite solid electrolyte (CSE) for a battery in various formats including a freestanding CSE separator, electrode-CSE laminate, current collector-CSE laminate, or CSE-based mixed ionic-electronic conductor (MIEC) electrode. The disclosure also relates to the methods of making composite solid electrolytes and batteries therewith. A CSE is disclosed having at least one polymer; at least one lithium salt; a solvent plasticizer; at least one inorganic additive particle; a substrate; and one or more liquid or solid additives. A method of making a CSE is disclosed as providing, as a liquid slurry, at least one polymer, at least one lithium salt, a solvent plasticizer, at least one inorganic additive particle, and one or more liquid or solid additives and coating a substrate with the liquid slurry.