LFP Battery Electrolyte Additives for Low-Temperature Cycling
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Solution Overview
Problem
The lithium iron phosphate battery exhibits low energy density and poor low-temperature performance, limiting its application scope compared to ternary batteries, despite its advantages in long-cycle performance and safety.
Innovation Solution
An electrolytic solution for lithium iron phosphate batteries is formulated by incorporating a phenyl sulfonate compound and vinylene carbonate, forming a sulfur-rich solid electrolyte interface (SEI) film that enhances low-temperature cycle performance and reduces impedance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium iron phosphate battery uses conventional electrolyte without phenyl sulfonate compound and vinylene carbonate, then the battery has simpler electrolyte composition, but the low-temperature cycle performance is poor and impedance is high
Solution Approach 1:
The patent applies composite materials by combining phenyl sulfonate compound and vinylene carbonate in the electrolyte formulation. This composite approach creates a synergistic effect where the phenyl sulfonate compound forms a sulfur-rich SEI film that prevents electrolyte decomposition, while vinylene carbonate enhances low-temperature ionic conductivity. Together, they resolve the contradiction by improving low-temperature cycle performance and reducing impedance without requiring complex structural modifications to the battery itself.
Solution Approach 2:
The patent employs parameter changes by optimizing the chemical composition parameters of the electrolyte, specifically incorporating phenyl sulfonate compound and vinylene carbonate at controlled concentrations. This changes the chemical and physical parameters of the electrolyte system, enabling it to maintain stable performance across a wider temperature range while reducing impedance, thereby improving reliability without excessive complexity.
2Stability of the object's composition
If lithium iron phosphate battery uses phenyl sulfonate compound and vinylene carbonate in electrolyte, then low-temperature cycle performance and stability are improved, but the electrolyte formulation becomes more complex
Solution Approach 1:
The patent uses composite materials by formulating the electrolyte with phenyl sulfonate compound and vinylene carbonate working together. The phenyl sulfonate compound provides stable SEI film formation, while vinylene carbonate contributes to electrolyte stability and low-temperature performance. This composite formulation achieves enhanced stability without requiring complex battery structural designs, only moderate formulation complexity.
Solution Approach 2:
The phenyl sulfonate compound acts as an intermediary substance that mediates between the electrode and electrolyte systems. It forms a protective sulfur-rich SEI film that stabilizes the interface, preventing direct contact and harmful reactions between the electrode and bulk electrolyte. This intermediary layer improves overall system stability while maintaining relatively simple electrolyte formulation.
3Duration of action of moving object
If lithium iron phosphate battery uses conventional electrolyte, then manufacturing process is simpler, but internal resistance is higher and cycle performance deteriorates
Solution Approach 1:
The patent applies preliminary action by incorporating phenyl sulfonate compound and vinylene carbonate into the electrolyte before battery assembly and operation. These additives proactively form protective films and stabilize the electrolyte system during initial cycles, preventing future degradation. This preliminary stabilization extends cycle life significantly compared to conventional electrolytes, while the manufacturing process remains relatively simple as it only requires standard electrolyte filling procedures.
Solution Approach 2:
The patent uses parameter changes by modifying the chemical composition parameters of the electrolyte to include phenyl sulfonate compound and vinylene carbonate. This changes the electrochemical properties of the system, leading to reduced internal resistance and extended cycle life. The manufacturing complexity increases only moderately, primarily involving precise measurement and mixing of electrolyte components, rather than complex manufacturing processes.
4Object-affected harmful factors
If lithium iron phosphate battery uses phenyl sulfonate compound additive, then impedance reduction is improved, but the electrolyte formulation requires precise composition control
Solution Approach 1:
The patent applies composite materials by combining phenyl sulfonate compound with vinylene carbonate in the electrolyte. This composite formulation achieves effective impedance reduction through synergistic action: phenyl sulfonate compound forms conductive sulfur-rich SEI film, while vinylene carbonate enhances overall ionic conductivity. The precise composition control required is moderate, as the benefits are achieved within a reasonable concentration range, balancing formulation precision with effective impedance management.
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 combined use of phenyl sulfonate and vinylene carbonate significantly improves low-temperature cycle performance, high-temperature cycle performance, and room-temperature cycle performance, while also reducing internal resistance and improving stability.
Implementation Method 1
forming a sulfur-rich solid electrolyte interface (SEI) film that enhances low-temperature cycle performance and reduces impedance
Implementation Method 2
The first additive in this scheme can effectively inhibit the reduction of the impedance of the battery, particularly the low-temperature impedance
Data Source
AI summary
An electrolytic solution for a lithium iron phosphate battery, and a lithium iron phosphate battery. The electrolytic solution includes a solvent, a lithium salt, a first additive and a second additive.