Fluorinated Carbonate Electrolyte for Nickel Cathode Cycle Stability
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Solution Overview
Problem
High-capacity and high-power nickel-based cathode materials in lithium-ion batteries face challenges in achieving long cycle life and thermal stability, particularly in automotive applications requiring at least 30,000 hours of service.
Innovation Solution
An electrolyte composition comprising fluorinated carbonates, a lithium-based salt, and a lithium (oxalato)borate salt is used to enhance the formation of a solid electrolyte interface (SEI) on the cathode, improving cycle life and thermal stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If nickel-based cathode materials with high capacity and high power are used, then energy density and power output are improved, but cycle life and thermal stability deteriorate
Solution Approach 1:
The patent introduces fluorinated carbonate additives (FEC, FEMC, FDEC, TFPC) as intermediary substances that mediate between the nickel-based cathode material and the electrolyte. These additives form a protective interface layer that stabilizes the cathode-electrolyte interface, preventing direct harmful interactions while allowing ionic conduction, thus improving cycle life without sacrificing the high power output capability of nickel-based cathodes
Solution Approach 2:
The patent modifies the chemical composition parameters of the electrolyte by incorporating specific fluorinated carbonate compounds with controlled concentrations (0.1-5 wt%). This parameter change alters the interfacial chemistry between the cathode and electrolyte, creating a more stable solid electrolyte interface (SEI) that enhances cycle life while preserving the high capacity and power characteristics of the nickel-based cathode material
2Power
If nickel-based cathode materials with high capacity and high power are used, then energy density and power output are improved, but thermal stability deteriorates
Solution Approach 1:
The fluorinated carbonate additives act as thermal intermediaries that form a protective interface layer between the nickel-based cathode and the electrolyte. This interface layer has superior thermal stability and acts as a thermal barrier, preventing uncontrolled thermal runaway reactions while allowing the battery to maintain high power output capability through the underlying nickel-based cathode material
Solution Approach 2:
The patent applies beforehand cushioning by pre-forming a stable solid electrolyte interface (SEI) layer using fluorinated carbonate additives before thermal runaway can occur. This pre-formed protective layer serves as a cushion against thermal degradation, delaying the onset of thermal runaway by up to 17°C as measured by differential scanning calorimetry, while preserving the high power characteristics of the nickel-based cathode
3Ease of manufacture
If conventional electrolyte compositions are used, then manufacturing simplicity is maintained, but cycle life and thermal stability are insufficient
Solution Approach 1:
The patent modifies the electrolyte composition parameters by adding small concentrations (0.1-5 wt%) of fluorinated carbonate additives to conventional electrolyte formulations. This parameter change maintains the overall simplicity of manufacturing while significantly improving cycle life through enhanced SEI formation at the cathode-electrolyte interface
Solution Approach 2:
The patent creates a composite electrolyte system by combining conventional electrolyte components with fluorinated carbonate additives. This composite approach leverages the proven performance of conventional electrolytes while introducing the thermal and cycle stability benefits of fluorinated compounds, achieving improved reliability without complicating the manufacturing process
4Ease of manufacture
If conventional electrolyte compositions are used, then manufacturing simplicity is maintained, but thermal runaway resistance is insufficient
Solution Approach 1:
The fluorinated carbonate additives serve as thermal intermediaries that form a stable interface layer between the cathode and electrolyte. This intermediate layer acts as a thermal barrier, preventing direct thermal runaway reactions while maintaining the simplicity of the overall manufacturing process by being incorporated into the existing electrolyte formulation
Solution Approach 2:
The patent applies beforehand cushioning by pre-forming a thermally stable solid electrolyte interface (SEI) layer using fluorinated carbonate additives during battery assembly. This pre-formed protective layer cushions against thermal runaway events, delaying peak temperatures by up to 17°C and reducing total heat release by 24%, while maintaining manufacturing simplicity through direct incorporation into conventional electrolyte processes
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 electrolyte composition enhances SEI formation, leading to improved cycle life and reduced thermal runaway risk, with peak temperatures delayed by up to 17°C and total heat release reduced by 24% compared to control compositions.
Implementation Method 1
The electrolyte composition provides lithium-ion conduction paths between the anode and the cathode. The electrolyte is an ionic conductor.
Implementation Method 2
An electrolyte composition comprising fluorinated carbonates, a lithium-based salt, and a lithium (oxalato)borate salt is used to enhance the formation of a solid electrolyte interface (SEI) on the cathode
Data Source
AI summary
An electrolyte composition for batteries is provided. The electrolyte composition includes a solvent including one or more fluorinated carbonates. The electrolyte composition further includes a lithium-based salt and a lithium (oxalato)borate salt. Additionally, a battery including the electrolyte composition is provided. The battery includes an anode, a nickel-based cathode, and the electrolyte composition disposed between the anode and the nickel-based cathode.