Silicon Anode Plate Structure for Low-Impedance Cycle Stability
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Solution Overview
Problem
Current battery technologies face challenges in increasing battery capacity and energy density while maintaining mechanical stability and reducing interface impedance, particularly in lithium batteries, where silicon anode materials experience volume changes and instability during charge and discharge processes.
Innovation Solution
An anode plate design featuring a carbon quantum dot layer with dots less than 10 nm, sandwiched between a silicon-containing coating layer and a graphite coating layer, applied on an anode current collector, enhances conductivity, flexibility, and mechanical properties, and reduces interface impedance, improving energy density and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If silicon anode materials are used to increase battery capacity and energy density, then energy density is improved, but volume changes and mechanical instability occur during charge and discharge processes
Solution Approach 1:
The patent applies a multi-layer nested structure where the silicon-containing coating layer is sandwiched between a carbon quantum dot layer and a graphite coating layer. This nested configuration allows the silicon material to expand and contract during lithium ion insertion and extraction while being constrained and protected by the surrounding carbon layers, thereby maintaining mechanical stability while preserving high capacity.
Solution Approach 2:
The patent creates a composite anode structure combining silicon-containing materials with carbon materials (carbon quantum dots and graphite). This composite approach leverages the high specific capacity of silicon while utilizing the mechanical stability and conductivity of carbon materials to counteract silicon's volume expansion issues, achieving both high energy density and structural stability.
2Quantity of substance
If silicon anode materials are used to increase battery capacity, then energy density is improved, but interface impedance increases and cycle life decreases
Solution Approach 1:
The patent introduces carbon quantum dots as an intermediary layer between the silicon-containing coating layer and the electrolyte. This intermediary layer facilitates efficient lithium ion transport while preventing direct contact between the electrolyte and silicon material, thereby reducing interface impedance and improving cycle life without compromising capacity.
Solution Approach 2:
The patent applies different materials with specific properties at different locations: carbon quantum dots at the interface for conductivity and stability, silicon-containing material in the middle for high capacity, and graphite coating on the outer surface for mechanical protection. This localized quality distribution optimizes both reliability and capacity.
3Stability of the object's composition
If conventional anode structures are used to maintain mechanical stability, then structural integrity is preserved, but energy density and conductivity are limited
Solution Approach 1:
The patent creates a composite anode structure combining silicon-containing materials with carbon materials (carbon quantum dots and graphite). This composite approach leverages the high specific capacity of silicon while utilizing the mechanical stability and conductivity of carbon materials to counteract silicon's volume expansion issues, achieving both high energy density and structural stability.
Solution Approach 2:
The patent applies a multi-layer nested structure where the silicon-containing coating layer is sandwiched between a carbon quantum dot layer and a graphite coating layer. This nested configuration allows the silicon material to expand and contract during lithium ion insertion and extraction while being constrained and protected by the surrounding carbon layers, thereby maintaining mechanical stability while preserving high capacity.
4Stability of the object's composition
If conventional anode structures are used to maintain structural integrity, then mechanical stability is preserved, but conductivity and rate performance are limited
Solution Approach 1:
The patent introduces carbon quantum dots as an intermediary layer between the silicon-containing coating layer and the electrolyte. This intermediary layer facilitates efficient lithium ion transport while preventing direct contact between the electrolyte and silicon material, thereby reducing interface impedance and improving cycle life without compromising capacity.
Solution Approach 2:
The patent applies different materials with specific properties at different locations: carbon quantum dots at the interface for conductivity and stability, silicon-containing material in the middle for high capacity, and graphite coating on the outer surface for mechanical protection. This localized quality distribution optimizes both reliability and capacity.
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 plate design effectively increases energy density, enhances mechanical stability, and improves cycle life and rate performance by reducing the risk of detachment and stabilizing the solid electrolyte interface film, while allowing for efficient lithium ion intercalation and deintercalation.
Implementation Method 1
allowing for efficient lithium ion intercalation and deintercalation
Implementation Method 2
stabilizing the solid electrolyte interface film
Data Source
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AI summary
Provided are an anode plate (100) and a fabrication method thereof, a battery cell (200), a battery (300) and an electronic device. The anode plate (100) includes an anode current collector (1); a carbon quantum dot layer (2), formed on a surface of the anode current collector (1); and an anode silicon-containing coating layer (3), formed on a surface of the carbon quantum dot layer (2) away from the anode current collector (1).