LiBOB Coated Negative Electrode for Battery Internal Resistance
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Solution Overview
Problem
Non-aqueous electrolyte secondary batteries experience deteriorated battery characteristics, including reduced capacity retention ratio and increased internal resistance, when used in high-temperature environments due to the variability in the state of the coating formed from lithium bis(oxalate)borate (LiBOB) on the negative electrode.
Innovation Solution
A non-aqueous electrolyte secondary battery with a negative electrode coated using lithium bis(oxalate)borate, where the boron to oxalate ion ratio in the coating is set to 5 or more, and a conditioning process involving repeated charging and discharging within specific state of charge ranges to stabilize the coating, is employed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lithium bis(oxalate)borate (LiBOB) is added to the non-aqueous electrolyte solution to form a coating on the negative electrode, then the battery characteristics are improved, but the state of the coating varies depending on generation conditions, leading to inconsistent effects
Solution Approach 1:
The patent applies parameter changes by precisely controlling the ratio of boron element to oxalate ion in the coating (setting it to 5 or more) and controlling the LiBOB additive amount (0.01 mass% to 1.0 mass%). This standardization of chemical parameters ensures consistent coating formation regardless of generation conditions, resolving the inconsistency in coating state while maintaining improved battery characteristics.
2Ease of manufacture
If the additive amount of LiBOB is defined, then the coating formation is controlled, but the effect due to coating formation changes depending on the state of the coating
Solution Approach 1:
The patent employs feedback by establishing a specific target ratio (boron element to oxalate ion ratio of 5 or more) that serves as a quality indicator. By monitoring and controlling this ratio along with the LiBOB additive amount, the patent ensures that the coating achieves the desired state and effect, creating a closed-loop control system that guarantees consistent results.
Solution Approach 2:
The patent transforms the manufacturing control approach by defining specific parameter ranges: LiBOB additive amount of 0.01 mass% to 1.0 mass% and boron element to oxalate ion ratio of 5 or more. These standardized parameters ensure that the coating effect remains consistent regardless of variations in generation conditions, resolving the reliability issue while maintaining ease of manufacture.
3Duration of action of moving object
If a coating is formed on the negative electrode to improve battery characteristics, then capacity retention ratio is enhanced, but internal resistance may increase due to coating variability
Solution Approach 1:
The patent resolves this contradiction by optimizing the chemical composition parameters of the coating: setting the boron element to oxalate ion ratio to 5 or more and the LiBOB additive amount to 0.01 mass% to 1.0 mass%. These parameter optimizations ensure that the coating enhances capacity retention ratio while preventing excessive internal resistance increase, achieving a balanced improvement in battery 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
This approach reliably improves battery characteristics by suppressing the increase in internal resistance and enhancing capacity retention ratio, ensuring consistent performance across varying environmental conditions.
Implementation Method 1
a coating derived from lithium bis(oxalate)borate is formed on the negative electrode through a conditioning process for charging and discharging
Data Source
AI summary
A non-aqueous electrolyte secondary battery according to the present invention includes a positive electrode, a negative electrode, and a non-aqueous electrolyte solution. The negative electrode includes a coating derived from lithium bis(oxalate)borate. The coating derived from lithium bis(oxalate)borate includes a coating containing boron element and a coating containing oxalate ion. A ratio of the boron element contained in the coating derived from lithium bis(oxalate)borate to the oxalate ion is equal to or more than 5. Accordingly, it is possible to provide a non-aqueous electrolyte secondary battery capable of reliably obtaining the effect due to the formation of a coating.