Core-Shell Battery Additive for LiPF6 Thermal Stability
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Solution Overview
Problem
Rechargeable lithium batteries face issues with thermal stability and safety due to the decomposition of LiPF6, leading to electrolyte depletion and high-temperature performance deterioration.
Innovation Solution
An additive for lithium batteries comprising a core with flame retardants and fire extinguishing agents, surrounded by a polymer shell with a melting point of 90°C to 120°C, which releases safety-enhancing materials at high temperatures to control ignition and prevent electrode short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LiPF6 is used as a lithium salt in the electrolyte, then high ionic conductivity and battery performance are achieved, but thermal decomposition occurs leading to electrolyte depletion and safety issues
Solution Approach 1:
The patent introduces a polymer coating as an intermediary layer between the LiPF6 lithium salt and the electrolyte solvent. This polymer coating acts as a protective mediator that prevents direct contact and decomposition reactions between LiPF6 and the solvent, thereby eliminating thermal decomposition while maintaining the high ionic conductivity benefits of LiPF6.
Solution Approach 2:
The patent modifies the physical and chemical parameters of the lithium salt by coating it with a polymer layer. This changes the surface properties and thermal stability parameters of LiPF6, raising its decomposition temperature and preventing harmful reactions with the electrolyte solvent while preserving its electrochemical performance.
2Object-affected harmful factors
If flame retardants are added to improve thermal stability, then safety is enhanced, but battery resistance increases and performance deteriorates
Solution Approach 1:
The patent extracts the flame-retardant function from bulk additive form and concentrates it into a thin polymer coating layer on the lithium salt surface. This localized extraction of the safety function prevents the need for large amounts of flame retardant additives in the bulk electrolyte, thereby avoiding increased resistance and performance deterioration.
Solution Approach 2:
The patent creates a composite material structure by combining the lithium salt core with a polymer coating shell. This composite structure integrates the high ionic conductivity of the lithium salt with the thermal stability and flame retardancy of the polymer coating, achieving both safety and performance enhancement without the drawbacks of mixing flame retardants into the bulk electrolyte.
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 additive enhances thermal stability and safety by maintaining battery characteristics without increasing resistance, effectively controlling ignition and preventing electrode short circuits.
Implementation Method 1
the shell includes a polymer having a melting point of 90 °C to 120 °C
Data Source
Figure 1~2
AI summary
Provided are an additive for a rechargeable lithium battery, an electrolyte a rechargeable lithium battery including the same, and a rechargeable lithium battery, the additive including a core, and a shell surrounding the core, wherein the core includes a flame retardant, a fire extinguishing agent, a non-combustible material, or a combination thereof, and the shell includes a polymer having a melting point of 90 °C to 120 °C.