Negative Electrode Coating and Electrolyte for Fast-Charging Li-Ion Batteries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithium-ion batteries face issues with lithium deposition at high charging rates, leading to rapid deterioration, increased self-discharge, and safety risks such as fire and explosion.
Innovation Solution
The battery design includes a negative electrode plate with a single-sided and double-sided region, where the electrolyte solution contains ethyl propionate and propyl propionate to improve conductivity and prevent lithium deposition. The thickness ratio of the single-sided to double-sided coating layers and the weight content of the organic solvents are optimized to enhance dynamics and prevent lithium deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the charging rate is increased to reduce charging time, then the charging speed is improved, but lithium deposition occurs on the negative electrode leading to rapid deterioration and safety accidents
Solution Approach 1:
The patent changes the chemical composition parameters of the electrolyte by introducing specific additives (boric acid and its derivatives) to modify the electrolyte's properties. This allows the battery to operate safely at high charging rates by preventing lithium deposition through chemical modification rather than changing the charging rate itself
Solution Approach 2:
The patent introduces electrolyte additives (boric acid and its derivatives) as intermediary substances that mediate between the high charging rate and the negative electrode. These additives form protective films on the electrode surface, acting as intermediaries that prevent direct lithium deposition while allowing charge transfer
2Manufacturing precision
If the thickness of the single-sided coating layer is reduced, then the manufacturing precision is improved, but the dynamics of the single-sided region deteriorates making it more prone to lithium deposition
Solution Approach 1:
The patent changes the chemical parameters of the electrolyte composition to compensate for the reduced coating thickness. By optimizing the electrolyte additive concentrations, the system maintains adequate dynamics and lithium deposition resistance even with thinner coating layers, enabling better manufacturing precision
3Speed
If the conductivity of the electrolyte solution is improved to increase charging rate, then the charging speed is improved, but the viscosity reduction may lead to poor dynamics in certain regions
Solution Approach 1:
The patent optimizes multiple electrolyte parameters simultaneously - not just conductivity but also viscosity and chemical composition. By carefully balancing these parameters through additive selection, the electrolyte maintains both high charging rate capability and adequate dynamics performance in all regions including single-sided areas
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
This design effectively prevents lithium deposition during cycling at 1C or higher charging rates, reduces self-discharge, improves battery stability and safety, and maintains good high-temperature cycling performance.
Implementation Method 1
by improving conductivity of an electrolyte solution and reducing viscosity
Implementation Method 2
by improving conductivity of an electrolyte solution and reducing viscosity
Implementation Method 3
the electrolyte solution includes an organic solvent, and the organic solvent includes ethyl propionate and/or propyl propionate
Data Source
AI summary
A battery includes a negative electrode plate and an electrolyte solution. The negative electrode plate includes a single-sided region and a double-sided region; the double-sided region is a double-side coated area, and a total thickness of double-sided coating layers is Y, in a unit of mm. and a thickness of a single-sided coating layer is X, in a unit of mm; a ratio A of a thickness of the single-sided coating layer to a thickness of the double-sided coating layers ranges from 0.5 to 0.65; the electrolyte solution includes ethyl propionate and/or propyl propionate; based on a total weight of the electrolyte solution, a content B wt % of the ethyl propionate ranges from 0 wt % to 50 wt %, and a content C wt % of the propyl propionate ranges from 0 wt % to 60 wt %; then, 2B+C≥400*(A−0.5).