Positive Electrode Plate Capacity Zoning for Edge Lithium Control
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Solution Overview
Problem
Lithium-ion batteries face challenges in increasing energy density while avoiding edge lithium precipitation on the negative electrode, which degrades battery performance.
Innovation Solution
A positive electrode plate design with distinct active material layers in the middle and edge regions, where the middle region has a higher specific capacity than the edge region, optimizing the distribution of materials to alleviate lithium precipitation and enhance cycling stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If surface density of electrode plates is increased to improve energy density, then energy density is improved, but edge lithium precipitation of negative electrode plate occurs causing performance deterioration
Solution Approach 1:
The patent applies local quality by creating different active material layer configurations in different regions of the positive electrode plate. The middle region has a first active material layer with higher specific capacity, while edge regions have a second active material layer with lower specific capacity. This local differentiation allows the electrode to achieve high overall energy density while the edge regions specifically prevent lithium precipitation, thus resolving the contradiction between energy density and performance stability.
Solution Approach 2:
The patent segments the positive electrode plate into distinct middle and edge regions with different active material layer structures. The middle region is optimized for high capacity storage, while edge regions are optimized for preventing lithium precipitation. This segmentation allows each region to perform its specialized function, enabling the overall electrode to achieve both high energy density and stable cycling performance without edge lithium precipitation.
2Use of energy by moving object
If surface density of electrode plates is increased to improve energy density, then energy density is improved, but cycling performance deteriorates due to edge lithium precipitation
Solution Approach 1:
The patent implements local quality by designing the positive electrode plate with region-specific active material layers. Edge regions contain a second active material layer with lower specific capacity that prevents lithium precipitation during cycling, while the middle region contains a first active material layer with higher specific capacity for maximum energy storage. This local differentiation ensures that edge regions protect against degradation mechanisms while the overall electrode maintains high energy density and excellent cycling performance.
Solution Approach 2:
The patent segments the electrode plate structure into functionally distinct middle and edge regions. The middle region is optimized for high capacity contribution to energy density, while edge regions are optimized for structural stability and prevention of lithium precipitation during charge-discharge cycles. This segmentation strategy enables the electrode to simultaneously achieve high energy density and durable cycling performance by assigning different functional roles to different spatial zones.
Data Source
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AI summary
The present disclosure relates to the field of battery technologies, and specifically, to a positive electrode plate and a battery including the same. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer disposed on either or both sides of the current collector. The positive electrode active material layer includes a first active material layer located in a middle region of a surface of the positive electrode current collector along a length direction and a second active material layer located at edges. A specific capacity of the first active material in the first active material layer is greater than that of the second active material in the second active material layer.