Lithium-Ion Battery Electrolyte Additives for Rate and Temperature Performance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithium-ion batteries face challenges in simultaneously improving high-rate discharge, low-temperature discharge, and high-temperature performance due to poor compatibility between positive-electrode materials and electrolytes, leading to compromised safety and performance.
Innovation Solution
A lithium-ion battery design incorporating a positive-electrode active material with Dv90 of 9.5±1.5 µm and an electrolyte additive comprising a tricarbonitrile and tetracarbonitrile compound, with specific weight ratios, to enhance compatibility and stability, thereby improving high-rate, low-temperature, and high-temperature performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional positive-electrode materials are combined with high-kinetics and low-impedance electrolytes, then high-rate discharge performance is improved, but low-temperature discharge performance and high-temperature performance cannot be simultaneously improved
Solution Approach 1:
The patent changes the particle size parameter of the positive-electrode active material to Dv90 of 9.5±1.5 μm, which is smaller than conventional materials. This parameter change enables simultaneous improvement of high-rate discharge performance (due to shorter ion diffusion paths) and low-temperature discharge performance (due to reduced activation energy requirements), while the specific particle size distribution maintains good high-temperature stability
Solution Approach 2:
The patent uses a composite electrolyte system comprising multiple components including LiPF6, LiBF4, LiCF3SO3 lithium salts, and a mixture of cyclic carbonates (EC, PC) and chain carbonates (DMC, DEC, EMC). This composite electrolyte formulation achieves compatible performance across different temperature ranges and discharge rates by combining the advantages of different electrolyte components
2Productivity
If specially-designed positive-electrode materials are used to improve high-rate discharge and low-temperature discharge properties, then these discharge properties are enhanced, but high-temperature performance is compromised
Solution Approach 1:
The patent optimizes the particle size parameter to Dv90 of 9.5±1.5 μm, which balances the competing requirements: small enough to provide short ion diffusion paths for high-rate performance and low activation energy for low-temperature performance, but not so small that surface effects dominate and cause instability at high temperatures. This specific parameter range resolves the contradiction between improved discharge properties and maintained high-temperature performance
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 combination of small-particle positive-electrode active materials with tricarbonitrile and tetracarbonitrile compounds stabilizes the electrode structure, preventing transition metal dissolution and enhancing discharge and temperature performance, ensuring safety and efficiency.
Implementation Method 1
the electrolyte comprises an electrolyte additive, and the electrolyte additive comprises a tricarbonitrile compound and a tetracarbonitrile compound
Implementation Method 2
the combination of small-particle positive-electrode active materials with tricarbonitrile and tetracarbonitrile compounds stabilizes the electrode structure, preventing transition metal dissolution
Implementation Method 3
the positive-electrode active layer comprises a positive-electrode active material with Dv90 of 9.5±1.5 μm
Implementation Method 4
the electrolyte comprises an electrolyte additive, and the electrolyte additive comprises a tricarbonitrile compound and a tetracarbonitrile compound
Data Source
AI summary
Provided are a lithium-ion battery and an electric device. The lithium-ion battery comprises a shell, and a cell and an electrolyte that are arranged inside the shell. The cell comprises a positive electrode, a negative electrode, and a separator arranged between the positive electrode and the negative electrode. The positive electrode comprises a positive-electrode active layer, and the positive-electrode active layer comprises a positive-electrode active material with Dv90 of 9.5±1.5 µm. The electrolyte comprises an electrolyte additive, and the electrolyte additive comprises a tricarbonitrile compound and a tetracarbonitrile compound. Compared with prior art, the lithium-ion battery provided by this application combines a specially-designed positive-electrode active material and an electrolyte additive, which can simultaneously improve the high-rate discharge performance, low-temperature discharge performance, and high-temperature performance of the lithium-ion battery.