Electrolyte Additives for High-Voltage Li-Ion Cycling Stability
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Solution Overview
Problem
Conventional lithium ion batteries face challenges in achieving high energy density, long battery life, and efficient discharge performance at high C-rates, especially under high voltage and temperature conditions.
Innovation Solution
The development of advanced electrolyte formulations incorporating specific additives, such as those represented by Formulas (A) to (H), which react with lithium salts to improve electrode stability and enhance cycling stability, discharge rate capability, and capacity retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If electrode thickness is increased to achieve higher energy density, then energy storage capacity is improved, but discharge performance at high C-rates deteriorates
Solution Approach 1:
The patent modifies the chemical composition parameters of the electrolyte by introducing specific additive compounds (Formulas A-H) with distinct molecular structures containing heteroatoms (O, N, S, F). These compositional changes enable the electrolyte to form stable interfacial films that facilitate ion transport, thereby resolving the contradiction between high energy density and high C-rate performance.
Solution Approach 2:
The electrolyte is formulated as a composite system combining multiple components: carbonates (cyclic and chain), carboxylic acid esters, and specialized additive compounds. This composite electrolyte formulation works synergistically to provide both high capacity retention and excellent discharge performance at high C-rates, as the different components address various aspects of electrode-electrolyte interface stability and ion conductivity.
2Quantity of substance
If operating voltage is increased to enhance energy storage, then energy density is improved, but cell lifetime under high voltage conditions deteriorates
Solution Approach 1:
The electrolyte additives (Formulas A-H) perform preliminary protective action by reacting with the electrode surfaces during initial cycles to form stable solid electrolyte interphase (SEI) films and protective layers. These pre-formed protective interfaces prevent further decomposition reactions during high-voltage operation, thereby extending cell lifetime while maintaining high energy density.
Solution Approach 2:
The additive compounds act as intermediary substances between the electrodes and the bulk electrolyte. They form interfacial protective layers that mediate the interaction between high-voltage electrodes and the electrolyte, preventing direct harmful reactions while allowing efficient ion transport. This intermediary function enables stable operation at high voltages without sacrificing energy density.
3Power
If operating temperature is increased to improve power capability, then power output is enhanced, but cell lifetime under high temperature conditions deteriorates
Solution Approach 1:
The patent introduces electrolyte additives with specific thermal stability parameters (Formulas A-H containing heteroatoms O, N, S, F). These compositional modifications enable the electrolyte to maintain stable interfacial films at elevated temperatures, allowing the battery to deliver high power output while resisting thermal degradation and extending cell lifetime under high-temperature conditions.
4Reliability
If electrolyte formulation is optimized for high voltage operation, then high voltage stability is improved, but discharge performance at high C-rates deteriorates
Solution Approach 1:
The electrolyte is designed as a composite formulation combining multiple functional components: carbonates for baseline stability, carboxylic acid esters for interfacial engineering, and specialized additives (Formulas A-H) for high-voltage protection. This composite approach creates synergistic effects where the combination provides both high-voltage stability and excellent high C-rate discharge performance, overcoming the trade-off between voltage stability and rate capability.
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
These electrolyte formulations demonstrate improved cycling stability, discharge rate capability, and capacity retention, particularly under extreme conditions such as high voltages and high temperatures, effectively addressing the limitations of conventional lithium ion batteries.
Implementation Method 1
incorporating specific additives, such as those represented by Formulas (A) to (H), which react with lithium salts to improve electrode stability
Data Source
AI summary
Provided herein are electrolyte additives and formulations for energy storage devices having improved performance. The improved performance may be realized as improved cycling stability at abusive testing conditions.