Non-Aqueous Secondary Battery Electrolyte for Uniform Electrode Reactions
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Solution Overview
Problem
Non-aqueous electrolyte secondary batteries experience uneven reaction distribution during repeated charging and discharging, leading to increased temperature in the central portion of the electrode assembly, which results in deteriorated cell properties.
Innovation Solution
The battery design incorporates a specific ratio of additive agent concentration in the positive and negative electrode active material layers, with a ratio of 1.4 to 2.6 in the end portion to central portion, and includes LiBOB or LiFSO3 as additive agents, ensuring uniform reaction by controlling the electrolyte solution distribution and impregnation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If the battery is repeatedly charged and discharged, then the cell capacity is utilized, but the temperature in the central portion increases and reaction becomes non-uniform, leading to deteriorated cell property
Solution Approach 1:
The patent applies local quality by creating a non-uniform concentration distribution of additive agents within the electrode active material layers. Specifically, the concentration of additive agents (such as LiBOB or LiFSO3) is made higher in the central portion region compared to the end portion region, with a concentration ratio A/B (end portion/central portion) controlled between 0.37 and 0.67. This local variation in chemical composition addresses the local temperature rise in the central portion during charging/discharging by providing additional lithium salt reservoirs where heat generation is most severe, thereby suppressing dendrite formation and maintaining uniform reaction distribution across different regions of the electrode assembly.
2Stability of the object's composition
If the concentration of additive agent is increased in the central portion to suppress temperature rise, then reaction uniformity improves, but the complexity of manufacturing increases
Solution Approach 1:
The patent employs preliminary action by pre-distributing additive agents (LiBOB or LiFSO3) in a non-uniform concentration pattern within the electrode active material layers before the battery is put into service. During the initial charging/discharging cycles, these pre-placed additive agents react and form protective films on the electrode surfaces, particularly in the central portion where temperature rise is most severe. This preliminary distribution strategy eliminates the need for complex real-time control systems or post-manufacturing adjustments, as the concentration gradient is built into the electrode structure during manufacturing, thereby achieving both reaction uniformity and manufacturing feasibility.
Solution Approach 2:
The patent applies parameter changes by controlling the concentration ratio A/B of additive agents between 0.37 and 0.67, where A is the concentration in the end portion region and B is the concentration in the central portion region. This specific parameter range optimizes the balance between suppressing central portion temperature rise and maintaining overall cell performance. By precisely controlling this concentration parameter within a defined range, the patent achieves uniform reaction distribution without requiring excessive complexity in the manufacturing process, as the concentration gradient can be established through controlled mixing or layering techniques during electrode fabrication.
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 suppresses cell property deterioration by maintaining uniform reaction across the electrode assembly, enhancing cycle capacity retention and reducing temperature-related reaction resistance differences.
Implementation Method 1
the electrolyte solution contains a lithium salt, a solvent, and an additive agent... in at least one of the positive electrode active material layer and the negative electrode active material layer, a ratio A/B of a concentration A of a component originated from the additive agent
Implementation Method 2
permeability of an electrolyte solution permeating from an end portion of a composite material layer in a negative electrode plate is set... a ratio A/B of a concentration A of a component originated from the additive agent in a region disposed on an end portion side in a width direction of the electrode assembly to a concentration B of the component originated from the additive agent in a region disposed in a central portion in the width direction
Data Source
AI summary
The present disclosure relates to a non-aqueous electrolyte secondary battery including an electrode assembly and an electrolyte solution, wherein the electrode assembly includes a positive electrode plate, a separator, and a negative electrode plate, the electrolyte solution contains a Li salt, a solvent, and an additive agent, the positive electrode plate includes a positive electrode core body and a positive electrode active material layer, the negative electrode plate includes a negative electrode core body and a negative electrode active material layer, and in at least one of the positive electrode active material layer and the negative electrode active material layer, a ratio A/B is 1.4 or more and 2.6 or less.