Phosphate-Based Battery Electrolyte for Stable Nickel-Rich Cathodes
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Solution Overview
Problem
Lithium secondary batteries face issues with reduced output and capacity due to damage to nickel-based lithium metal oxide cathode active materials and side reactions with the electrolyte, as well as instability at extreme temperatures, necessitating improved safety, lifespan, and performance characteristics.
Innovation Solution
Incorporation of a phosphate-based additive in the electrolyte, comprising compounds represented by specific formulas, which form a protective film on the cathode and anode surfaces, enhancing stability and capacity characteristics across various temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If nickel-based lithium metal oxide is used as cathode active material to achieve high capacity, then battery capacity is improved, but damage to cathode surface and side reactions with electrolyte occur reducing lifespan and stability
Solution Approach 1:
The phosphate-based additive performs preliminary action by forming a protective film on the cathode surface before the cathode material can be damaged or undergo harmful side reactions with the electrolyte. This pre-formed protective layer prevents subsequent degradation during charging and discharging cycles.
Solution Approach 2:
The phosphate-based additive acts as an intermediary between the nickel-based lithium metal oxide cathode and the electrolyte. It forms a protective interface layer that mediates the interaction, preventing direct harmful contact while allowing beneficial electrochemical reactions to proceed.
2Device complexity
If conventional electrolyte composition is used to maintain simplicity, then device complexity is low, but safety and performance characteristics deteriorate
Solution Approach 1:
The electrolyte uses a composite material approach by combining the conventional electrolyte base with a phosphate-based additive. This composite composition integrates the benefits of simple conventional electrolytes with the protective and performance-enhancing properties of the phosphate additive.
Solution Approach 2:
The invention applies parameter changes by modifying the electrolyte composition through the addition of phosphate-based compounds. This changes the chemical parameters of the electrolyte system to achieve improved safety and performance characteristics while maintaining practical simplicity.
3Adaptability or versatility
If battery operates in severe high or low temperature environment to meet application requirements, then adaptability is improved, but stability deteriorates due to side reactions
Solution Approach 1:
The phosphate-based additive provides preliminary anti-action by preemptively forming a stable protective film on the cathode surface that resists degradation from high or low temperature environments. This pre-formed protective layer counteracts the destabilizing effects of extreme temperatures before they can cause harm.
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 phosphate-based additive improves initial capacity, low-temperature, and high-temperature performance by reducing internal resistance and maintaining stable capacity and lifespan characteristics.
Implementation Method 1
the phosphate-based additive comprises a compound represented by Formula 1 below... which form a protective film on the cathode and anode surfaces
Implementation Method 2
an electrolyte in which the electrode assembly is impregnated... a lithium secondary battery which provides uniform output and capacity even during repeated charging and discharging
Data Source
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AI summary
An electrolyte for a lithium secondary battery including an organic solvent, a lithium salt, and a phosphate-based additive including a compound represented by Formula 1. A lithium secondary battery according to embodiments of the present disclosure may include a cathode, an anode opposite to the cathode, and an electrolyte including the phosphate-based additive represented by Formula 1.