Fluorinated Electrolyte Additive for High-Potential Battery Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium ion secondary batteries face challenges in suppressing oxidation and decomposition of organic solvents on the positive electrode surface during high-potential driving, which affects battery performance and safety.
Innovation Solution
Incorporating a compound represented by General Formulae (I) to (III) into the electrolytic solution, which includes transition metals like Ti, Zr, or Hf, to form a solid electrolyte interphase (SEI) coating on the positive electrode, effectively preventing oxidation and decomposition at higher potentials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the battery is driven at high potential to increase energy density, then the energy capacity is improved, but oxidation and decomposition of organic solvent occurs on the positive electrode surface
Solution Approach 1:
The patent introduces a fluorinated cyclic carbonate compound as an intermediary substance that forms a protective SEI coating on the positive electrode surface. This intermediary layer acts as a barrier between the high-potential electrode and the organic solvent, preventing direct contact and thus preventing oxidation and decomposition while allowing the battery to operate at high potential for increased energy capacity
Solution Approach 2:
The fluorinated cyclic carbonate compound performs preliminary protective action by forming a stable SEI coating on the positive electrode surface before the organic solvent can undergo oxidation and decomposition. This pre-formed protective layer prevents the harmful reactions that would otherwise occur during high-potential charging, enabling safe operation at higher potentials for improved energy density
2Reliability
If conventional additives are used to form SEI coating, then the cycle characteristics are improved at approximately 4 V, but the SEI coating is insufficient at higher potentials
Solution Approach 1:
The patent changes the chemical parameters of the additive by introducing fluorinated cyclic carbonate compounds with specific molecular structures (Formulae I-III) containing fluorine atoms and specific functional groups. These parameter changes in the additive's chemical composition enable the formation of stable SEI coatings at higher potentials (5 V or more) compared to conventional additives that only work effectively at around 4 V, thus improving both cycle characteristics and adaptability across different potential ranges
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 effectively suppresses the oxidation and decomposition of organic solvents on the positive electrode surface, enhancing the battery's cycle characteristics and safety, even at high potentials, thereby improving the battery's performance and service life.
Implementation Method 1
the formation of a solid electrolyte interphase (SEI) coating on the positive electrode surface at a high potential is considered to be effective
Implementation Method 2
it is necessary to suppress the oxidation and decomposition of an organic solvent or the like that is included in an electrolytic solution on the positive electrode surface during the high-potential driving
Data Source
AI summary
Provided is an electrolytic solution for a non-aqueous secondary battery containing an electrolyte, an organic solvent, and a compound represented by any of General Formulae (I) to (III) and a non-aqueous secondary battery in which the electrolytic solution for a non-aqueous secondary battery is used.In the formulae, M represents a transition metal.R1, R2, and R3 represent a specific substituent. a represents an integer of 0 to 5. b represents an integer of 0 or more. c represents an integer of 0 to 5.Ar1 represents an aromatic ring. In General Formula (II), a plurality of Ar1's may be linked together.Ar2 represents a nitrogen-containing aromatic hetero ring.