Lithium Battery Negative Electrode with Dielectric Dendrite Barrier
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Solution Overview
Problem
Lithium secondary batteries experience a reduction in capacity retention rate due to irreversible reactions of lithium metal, necessitating an improvement in capacity retention.
Innovation Solution
Incorporation of a dielectric particle in the negative electrode layer, which is in contact with the negative electrode current collector, to reduce dendrite growth and enhance the capacity retention rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If lithium metal is used as negative electrode active material, then high output voltage is achieved, but capacity retention rate decreases due to irreversible reaction
Solution Approach 1:
A dielectric particle is introduced as an intermediary substance between the lithium metal and the current collector. This dielectric particle prevents direct contact and irreversible reaction between lithium metal and the current collector, thereby improving capacity retention rate while maintaining the high output voltage benefit of lithium metal.
Solution Approach 2:
The negative electrode is constructed as a composite structure combining lithium metal, dielectric particle, and current collector. This composite design allows the system to utilize the high voltage advantage of lithium metal while the dielectric component protects against capacity degradation through irreversible reactions.
2Reliability
If dielectric particle is added to negative electrode layer, then capacity retention rate improves, but device complexity increases
Solution Approach 1:
The dielectric particle is applied locally at the critical interface between lithium metal and current collector where irreversible reactions occur. This localized approach improves capacity retention rate without requiring the entire negative electrode structure to be complex, thereby minimizing the increase in device complexity.
3Reliability
If dielectric particle is in contact with current collector, then dendrite growth is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent requires that the dielectric particle be in contact with at least a part of the current collector, rather than requiring complete coverage or precise positioning throughout. This partial action approach effectively reduces dendrite growth while relaxing manufacturing precision requirements, making the invention more feasible for practical production.
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 addition of dielectric particles improves the capacity retention rate of lithium secondary batteries by reducing battery resistance and dendrite growth, thereby enhancing the battery's cycle characteristics.
Implementation Method 1
the dielectric particle may have a relative dielectric constant of 10 to 600
Data Source
AI summary
A negative electrode for a lithium secondary battery includes a negative electrode current collector and a negative electrode layer. The negative electrode layer includes a dielectric particle and a negative electrode active material including either or both of a lithium metal and a lithium alloy.