Anode Concentration Gradient for Capacity Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Batteries face capacity degradation due to charge and discharge cycles, requiring an anode with improved capacity durability.
Innovation Solution
An anode with a Li composite layer containing a Li element and a dope element, where the concentration of the dope element is higher on the anode current collector side compared to the opposite side, providing a concentration gradient that enhances capacity durability and reduces battery resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a uniform Li composite layer is used in the anode, then the manufacturing process is simple, but the capacity durability is poor due to crack formation during charge and discharge cycles
Solution Approach 1:
The patent applies local quality by creating a non-uniform concentration distribution of the dope element within the Li composite layer. The concentration is specifically designed to be higher near the current collector and lower toward the electrolyte interface, allowing different regions to perform different functions: the high-concentration region near the current collector prevents crack formation and maintains structural integrity, while the low-concentration region near the electrolyte interface facilitates efficient Li ion insertion and extraction. This spatial variation in composition directly resolves the technical contradiction by improving capacity durability through localized structural stabilization without requiring complex manufacturing processes.
Solution Approach 2:
The patent employs parameter changes by systematically varying the concentration of the dope element as a continuous parameter throughout the Li composite layer thickness. By controlling the concentration gradient (with C2 > C1 as specified in the claims), the patent optimizes the mechanical and electrochemical properties of different regions. This parameter variation allows the material to simultaneously exhibit crack-resistance near the current collector and high ion conductivity near the electrolyte, thereby improving capacity durability while maintaining manufacturing feasibility through controlled compositional adjustment.
2Strength
If the dope element concentration is increased throughout the Li composite layer, then crack formation is inhibited, but Li ion dispersion and electrochemical performance deteriorate
Solution Approach 1:
The patent resolves this contradiction by applying local quality through spatially differentiated dope element concentration. The high concentration region is localized near the current collector where structural integrity is most critical for preventing crack formation during volume changes. Conversely, the low concentration region is positioned near the electrolyte interface where unimpeded Li ion diffusion and insertion/extraction are paramount for electrochemical performance. This localized composition strategy ensures that each region optimizes its primary function without compromising the other.
Solution Approach 2:
The patent utilizes dimensional variation by transitioning from a uniform one-dimensional layer to a compositionally graded structure with continuous or stepwise concentration variation through the layer thickness. This dimensional approach to composition control allows the dope element concentration to be optimized at different positions (depth) within the layer, enabling simultaneous achievement of structural integrity near the current collector and efficient ion dispersion near the electrolyte interface, thereby resolving the contradiction between strength and productivity.
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 anode exhibits excellent capacity durability and reduced battery resistance, with the concentration gradient of the dope element improving Li ion dispersion and inhibiting crack formation due to volume changes during charging and discharging.
Implementation Method 1
the concentration of the dope element has the relation of C2>C1... improving Li ion dispersion
Data Source
AI summary
A main object of the present disclosure is to provide an anode with excellent capacity durability. The present disclosure achieves the object by providing an anode including an anode current collector, and an anode active material layer arranged on the anode current collector, wherein: the anode active material layer includes a Li composite layer containing a Li composite including a Li element and a dope element; and in the Li composite layer, when C1 designates a concentration of the dope element in a first surface that is an opposite side of the anode current collector side, and C2 designates a concentration of the dope element in a second surface that is the anode current collector side, the C2 is larger than the C1.