Secondary Battery Electrolyte Composition for Stable Interface Films
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Solution Overview
Problem
Current secondary batteries, particularly those using lithium iron phosphate positive electrode materials, face challenges in enhancing cycling performance, storage performance, and kinetic performance to meet the increasing demands of power and energy storage applications.
Innovation Solution
Incorporating specific amounts of vinylene carbonate in the electrolyte and carbon element in the positive electrode active material, along with additional additives like nitrogen-containing heterocyclic compounds, isocyanate compounds, acid anhydride compounds, silane compounds, and nitrogen-containing heterocyclic boron trifluoride complexes, to form high-quality electrolyte interface films that enhance ion and electron conductivity while reducing electrolyte consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium iron phosphate positive electrode materials are used, then safety performance and service life are improved, but cycling performance and kinetic performance deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters by introducing vinylene carbonate at 0.1-3% mass percentage and carbon elements at 0.5-6% mass percentage in the positive electrode active material. These parameter modifications transform the electrode interface properties, enabling lithium iron phosphate to achieve both high safety and improved cycling performance through optimized composition ratios.
Solution Approach 2:
The patent creates a composite structure by combining lithium iron phosphate with vinylene carbonate and carbon elements. This composite approach allows the system to inherit the safety and longevity benefits of lithium iron phosphate while gaining the kinetic performance and conductivity improvements from vinylene carbonate and carbon additives.
2Productivity
If electrolyte additives are increased to improve cycling performance, then electrolyte consumption increases
Solution Approach 1:
The patent optimizes the concentration parameter of vinylene carbonate to a precise range of 0.1-3% mass percentage. Within this optimized parameter range, the electrolyte forms effective protective films that improve cycling performance while minimizing electrolyte consumption through efficient film formation that prevents further electrolyte decomposition.
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 results in secondary batteries with improved cycling performance, storage performance, and kinetic performance by forming stable films that suppress side reactions and maintain conductivity, thereby supporting better charge and discharge performance across various temperatures.
Implementation Method 1
the electrolyte and the positive electrode plate in the secondary battery provided in this application satisfy the above characteristics, enabling simultaneous enhancement of ion conductivity and electron conductivity of the secondary battery, as well as reduction of a consumption rate of the electrolyte
Implementation Method 2
based on a total mass of the positive electrode active material, a mass percentage b of the carbon element is 0.5% to 6%. The electrolyte and the positive electrode plate in the secondary battery provided in this application satisfy the above characteristics, enabling simultaneous enhancement of ion conductivity and electron conductivity
Implementation Method 3
the electrolyte further includes a nitrogen-containing heterocyclic compound, and based on the total mass of the electrolyte, a mass percentage c of the nitrogen-containing heterocyclic compound is 0.01% to 1%. By controlling the mass percentage c of the nitrogen-containing heterocyclic compound within the above range, the cycling performance of the secondary battery can be improved
Data Source
AI summary
A secondary battery includes a positive electrode plate, a negative electrode plate, and an electrolyte. The electrolyte includes vinylene carbonate, and based on a total mass of the electrolyte, a mass percentage a of the vinylene carbonate is 0.1% to 3%. The positive electrode plate includes a positive electrode active material, the positive electrode active material includes carbon element, and based on a total mass of the positive electrode active material, a mass percentage b of the carbon element is 0.5% to 6%.