Conducting Polymer Network-Protected Cathode Particulates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithium-ion batteries face limitations in energy density, power density, cycle life, and safety due to drawbacks in cathode active materials, including low specific capacity, thermal runaway risks, and structural instability caused by volume changes during charging and discharging.
Innovation Solution
Development of cathode particulates with a conducting polymer network composite, where primary particles of cathode active materials are encapsulated by cross-linked conjugated polymer chains, providing enhanced lithium ion and electron conductivity, and reinforced with graphene or carbon materials to stabilize the structure and prevent electrolyte interaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high-capacity cathode active materials (e.g., metal fluorides, metal chlorides) are used to increase specific capacity, then energy density is improved, but structural instability occurs due to large volume expansion and shrinkage during charging and discharging
Solution Approach 1:
The cathode active material particles are encapsulated within a conducting polymer network matrix, forming a nested structure where the active material is protected inside the polymer shell. This nested configuration allows the polymer network to accommodate volume changes of the inner active material particles during lithiation and delithiation, preventing structural collapse and maintaining electrochemical performance.
Solution Approach 2:
The invention creates a composite structure consisting of conducting polymer network (e.g., polyaniline, polypyrrole, polythiophene) combined with cathode active materials (e.g., LiCoO2, LiMn2O4, metal fluorides). The composite leverages the high capacity of inorganic materials and the structural flexibility of conducting polymers, achieving both high energy density and structural stability during cycling.
2Ease of manufacture
If conventional cathode active materials are used to achieve practical capacity, then battery can be manufactured, but thermal runaway risk increases due to high oxygen content that assists electrolyte oxidation
Solution Approach 1:
The conducting polymer network serves as an intermediary layer between the cathode active material and the electrolyte. This intermediate polymer shell prevents direct contact and harmful interactions between the oxygen-rich active material and the electrolyte, thereby suppressing thermal runaway while maintaining the manufacturability of conventional cathode materials.
Solution Approach 2:
The conducting polymer network creates an inert protective environment around the cathode active material particles, isolating them from the electrolyte and preventing oxidative reactions. This inert barrier reduces thermal runaway risk while allowing the use of conventional cathode materials that would otherwise be problematic.
3Ease of manufacture
If conventional cathode active materials are used to achieve practical capacity, then battery can be manufactured, but capacity loss occurs due to dissolution of active material in electrolyte and undesirable reactions
Solution Approach 1:
The cathode active material particles are nested within the conducting polymer network matrix, which acts as a protective shell preventing dissolution of the active material into the electrolyte. This nested configuration maintains the integrity of the active material during cycling, improving cycle life while preserving the manufacturability of conventional materials.
Solution Approach 2:
The conducting polymer network functions as an intermediary barrier between the cathode active material and the electrolyte, preventing direct contact that would cause dissolution and undesirable chemical reactions. This intermediary layer enhances reliability and cycle life without affecting the ease of manufacturing conventional cathode materials.
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 solution significantly improves energy density, cycle life, and safety by maintaining structural integrity and preventing electrolyte decomposition, leading to more stable and efficient lithium-ion battery performance.
Implementation Method 1
an electrically and ionically conducting network of cross-linked conjugated polymer chains having a lithium ion conductivity from 10−8 S/cm to 5×10−2 S/cm
Implementation Method 2
an electrically and ionically conducting network of cross-linked conjugated polymer chains having a lithium ion conductivity from 10−8 S/cm to 5×10−2 S/cm and an electron conductivity from 10−8 to 103 S/cm
Implementation Method 3
cross-linked conjugated polymer chains
Data Source
AI summary
The disclosure provides multi-functional cathode particulates for a lithium battery, wherein at least one of the particulates has a diameter from 100 nm to 50 μm and comprises a conducting polymer network composite comprising one or a plurality of primary particles of a cathode active material that are partially or fully encapsulated by, embedded in, dispersed in, or bonded by an electrically and ionically conducting network of cross-linked polymer chains having a lithium ion conductivity from 10−8 to 5×10−2 S/cm and an electron conductivity from 10−8 to 103 S/cm, wherein the primary particles have a diameter or thickness from 0.5 nm to 20 μm. Also provided is a method of producing such cathode particulates.