Battery Electrolyte Passivation Layer Formation for Manganese Ion Suppression
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Solution Overview
Problem
Batteries with transition metal positive electrodes and graphite negative electrodes face performance degradation due to manganese ion deposition at high temperatures, leading to reduced cycling performance and increased self-discharge.
Innovation Solution
Incorporating a lithium-based electrolyte with passivation salts and additives, such as lithium bis(oxalato)borate and vinyl carbonate, which form stable passivation layers on the negative electrode during charge and discharge, preventing manganese ion deposition and enhancing battery performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high current draw is applied to the battery, then power output is improved, but temperature increases causing manganese ion dissolution and deposition
Solution Approach 1:
The patent introduces passivation salts (lithium borate, lithium fluoride) and passivation additives (vinyl carbonate, fluoroethylene carbonate) as intermediary substances in the electrolyte. These intermediaries form protective passivation layers on the negative electrode surface, which act as a barrier between the electrode and manganese ions in the electrolyte. This mediator layer prevents harmful manganese ion deposition while allowing the battery to operate at high currents and temperatures without performance degradation.
2Reliability
If manganese ions deposit on the negative electrode, then battery performance degrades, but this occurs at high temperatures
Solution Approach 1:
The patent applies preliminary anti-action by incorporating passivation salts and additives into the electrolyte that proactively form protective passivation layers on the negative electrode before manganese ions can deposit. This preventive measure creates a stable protective barrier that actively resists manganese ion deposition, thereby maintaining battery performance and preventing capacity loss even at elevated temperatures where such deposition would normally occur.
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 stabilizes the passivation layer, improving cycling performance and reducing self-discharge, thus maintaining battery capacity and efficiency under high temperature and high current conditions.
Implementation Method 1
Incorporating a lithium-based electrolyte with passivation salts and additives, such as lithium bis(oxalato)borate and vinyl carbonate, which form stable passivation layers on the negative electrode during charge and discharge
Implementation Method 2
At least one of the passivation salts forms a passivation layer on the negative electrode during charge of the battery
Data Source
AI summary
The battery includes an electrolyte activating a positive electrode and a negative electrode. The electrolyte includes a plurality of salts in a solvent, one or more passivation salts in the solvent, and one or more passivation additives in the solvent. At least one of the passivation salts forms a passivation layer on the negative electrode during discharge of the battery and includes both lithium and boron. At least one of the salts is an inorganic lithium salt that excludes boron. The solvent includes one or more organic solvents. At least one of the passivation additives forms a passivation layer on the negative electrode during discharge of the battery and is not a salt. The positive electrode has one or more positive active materials that each include a lithium transition-metal oxide and the negative electrodes includes a negative active material selected from a group consisting of lithium metal and graphite.