Battery Ion Barrier Layer for Dendrite Control
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Solution Overview
Problem
Lithium-ion batteries face design limitations due to Li ion accumulation at the edges of the negative electrode, leading to dendrite formation, which reduces battery reliability and safety, and necessitates a larger negative electrode size, thereby limiting capacity.
Innovation Solution
Incorporating a barrier layer on the positive electrode to control ion transfer, with a thinner edge area and an insulation layer to suppress electron movement, enhancing ion storage capacity while preventing dendrite formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the positive and negative electrodes are made the same size for efficient design, then manufacturing efficiency is improved, but Li ion accumulation occurs at the negative electrode edge causing dendrite formation and reduced reliability
Solution Approach 1:
The patent applies local quality by creating a non-uniform positive electrode structure with different thickness regions: a first area with greater thickness at the center and a second area with lesser thickness at the edge. This localized variation in electrode geometry prevents Li ion accumulation at the negative electrode edge while maintaining overall manufacturing efficiency, as the positive electrode still covers the same area as the negative electrode.
2Reliability
If the negative electrode is made larger to prevent Li ion accumulation, then dendrite formation is reduced, but battery capacity is limited and design flexibility is reduced
Solution Approach 1:
Instead of making the negative electrode larger, the patent modifies the positive electrode's local geometry to have varying thickness. This approach maintains equal electrode areas for maximum capacity while preventing dendrite formation through the non-uniform positive electrode structure, thereby avoiding the capacity limitations that would result from an oversized negative electrode.
3Reliability
If a barrier layer is added to control ion transfer, then dendrite formation is suppressed, but device complexity increases
Solution Approach 1:
The patent implements dendrite suppression through local geometric modification of the positive electrode rather than adding a separate barrier layer. By creating thickness variations within the existing electrode structure, the patent achieves dendrite prevention while maintaining structural simplicity and avoiding the complexity of additional protective layers.
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 effectively increases the positive electrode active material area, enhances battery capacity, and reduces ion dendrite-related side effects, improving both reliability and safety by controlling ion transfer paths.
Implementation Method 1
a barrier layer configured to suppress transfer of ions from the positive electrode active material-coated positive electrode mixture layer
Implementation Method 2
The lithium-ion battery may convert chemical energy into electrical energy by redox reactions at the positive and negative electrodes
Data Source
AI summary
A battery includes: a negative electrode including a negative electrode substrate layer and a negative electrode active material-coated negative electrode mixture layer on the negative electrode substrate layer; a positive electrode facing the negative electrode, the positive electrode including: a positive electrode substrate layer; a positive electrode active material-coated positive electrode mixture layer provided on the positive electrode substrate layer; and a barrier layer configured to suppress transfer of ions from the positive electrode active material-coated positive electrode mixture layer; and a separator provided between the negative electrode and the positive electrode, wherein the positive electrode active material-coated positive electrode mixture layer includes a first area at a center area of the positive electrode active material-coated positive electrode mixture layer and a second area at an edge of the positive electrode active material-coated positive electrode mixture layer, and wherein the barrier layer covers at least a portion of the second area and is further configured to limit direct transfer of the ions from the first area to the negative electrode.