Lithium Battery Electrolyte Additive for High-Current Electrode Wetting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Increasing the current density of the positive electrode plate in rechargeable lithium batteries to achieve high capacity leads to reduced wettability with the electrolyte, resulting in lithium dendrite precipitation on the negative electrode plate, which deteriorates cycle-life characteristics and rapid charging performance.
Innovation Solution
Incorporating a polyalkylene glycol-based copolymer as an electrolyte additive that acts as a surfactant, improving the wettability of the positive electrode plate and uniformly distributing lithium cations at the interface, thereby suppressing lithium dendrite precipitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the current density of the positive electrode plate is increased to achieve high capacity, then the energy density is improved, but the wettability of the positive electrode plate to the electrolyte deteriorates
Solution Approach 1:
A surfactant is introduced as an intermediary substance between the positive electrode plate and the electrolyte. The surfactant molecules position themselves at the interface, with hydrophilic groups interacting with the electrolyte and hydrophobic groups interacting with the electrode plate surface, thereby improving wettability without requiring a reduction in current density
Solution Approach 2:
The surface properties of the positive electrode plate are modified by changing the chemical composition at the interface through surfactant adsorption. This alters the surface energy and wettability parameters, allowing the electrode to maintain good electrolyte contact even at high current densities
2Use of energy by moving object
If the current density of the positive electrode plate is increased to achieve high capacity, then the energy density is improved, but lithium dendrite precipitation on the negative electrode plate occurs, deteriorating cycle-life characteristics and rapid charging performance
Solution Approach 1:
The surfactant is introduced in advance to prevent the formation of lithium dendrites. By improving wettability and ensuring uniform lithium ion distribution at the positive electrode plate interface, the surfactant prevents the concentration gradients that would otherwise lead to dendrite precipitation on the negative electrode plate during high-rate charging
Solution Approach 2:
The surfactant acts as a mediator that ensures uniform lithium ion extraction from the positive electrode plate. This prevents localized high current density regions that would drive lithium plating and dendrite formation on the negative electrode, thereby protecting cycle-life characteristics
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
Enhances cycle-life characteristics and rapid charging performance by maintaining high capacity while preventing lithium dendrite formation, even at increased current densities.
Implementation Method 1
the electrolyte additive serves as a surfactant. Accordingly, in the rechargeable lithium battery including the electrolyte additive, even though the current density of the positive electrode plate is increased, the wettability of the positive electrode plate to the electrolyte may be improved
Implementation Method 2
the wettability of the positive electrode plate to the electrolyte may be improved
Implementation Method 3
lithium cations (Li+) are uniformly (or substantially uniformly) formed at the interface between the positive electrode plate and the electrolyte
Data Source
AI summary
Disclosed are a rechargeable lithium battery including a positive electrode plate; a negative electrode plate; and an electrolyte including an electrolyte additive, in which the current density of the positive electrode plate and the electrolyte additive are controlled, respectively. Details about the current density of the positive electrode plate and the electrolyte additive are as described in the specification.