Negative Electrode Plate With Dielectric Layer for Interface Stability
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Solution Overview
Problem
Existing electrochemical devices face issues with side reactions between the electrolyte and the negative electrode interface, leading to decomposition of the electrolyte, gas production, and a rapid decay in cycle life, along with safety concerns such as short circuits due to metal dendrite formation.
Innovation Solution
A negative electrode plate is developed with an inorganic dielectric layer between the negative active material layer and the separator, which stabilizes the negative electrode interface, reduces side reactions, and inhibits gas production, thereby enhancing safety and cycle performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If no protective layer is added to the negative electrode, then the structure remains simple and manufacturing cost is low, but side reactions between electrolyte and negative electrode interface occur frequently, causing electrolyte decomposition and gas production
Solution Approach 1:
An inorganic dielectric layer is introduced as an intermediary between the negative electrode and electrolyte. This layer acts as a protective mediator that prevents direct contact between the electrolyte and negative electrode active material, thereby eliminating side reactions and gas production while extending cycle life.
Solution Approach 2:
The inorganic dielectric layer is formed on the negative electrode surface before the electrode is assembled into the battery. This preliminary protective action prevents harmful side reactions from occurring during subsequent battery operation, addressing the reliability issue before it manifests.
2Reliability
If no protective layer is added to the negative electrode, then the manufacturing process remains simple, but metal dendrites form on the negative electrode interface, inducing short circuits and deteriorating safety performance
Solution Approach 1:
The inorganic dielectric layer serves as a protective intermediary that prevents metal dendrite formation by blocking direct interaction between the electrolyte and negative electrode interface, thereby eliminating short circuit risks and improving safety performance.
Solution Approach 2:
The inorganic dielectric layer is applied in advance to the negative electrode surface, creating a protective cushion that prevents harmful effects (dendrite formation and short circuits) before they can occur during battery operation.
3Duration of action of moving object
If the negative electrode interface is not stabilized, then the electrode structure remains simple, but irreversible capacity increases continuously, causing rapid decay of cycle life
Solution Approach 1:
The inorganic dielectric layer acts as a protective intermediary that prevents the continuous consumption of electrolyte cations by blocking side reactions at the negative electrode interface, thereby reducing irreversible capacity and extending cycle life.
Solution Approach 2:
The harmful side reactions and gas production are extracted/eliminated from the system by introducing the inorganic dielectric layer, which separates the negative electrode from the electrolyte and prevents the continuous loss of electrolyte cations.
4Reliability
If the transmission performance of electrolyte cation in negative electrode is poor, then the electrode structure remains simple, but metal dendrites form on the negative electrode interface, inducing short circuits
Solution Approach 1:
The inorganic dielectric layer serves as a protective intermediary that prevents metal dendrite formation by blocking direct interaction between the electrolyte and negative electrode interface, thereby eliminating short circuit risks and improving safety performance.
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 proposed solution effectively stabilizes the negative electrode interface, reduces irreversible capacity, and improves the kinetic performance of the electrochemical device, resulting in enhanced safety, cycle, and high-temperature performance.
Implementation Method 1
an inorganic dielectric layer 13 which is disposed on a surface of the negative active material layer 12 facing away from the negative current collector 11 and comprises an inorganic dielectric material
Implementation Method 2
disposing an inorganic dielectric layer (13) on a surface of the negative active material layer (12) facing away from the negative current collector (11) by vapor deposition
Implementation Method 3
the negative electrode plate 10 has a compact density of from 1.2 g/cm 3 to 2.0 g/cm 3 and has ion permeability and electron conductivity
Data Source
Figure 1~2
Figure 3A~3C
Figure 4~5
AI summary
The invention refers to negative electrode plate (10), preparation method thereof and electrochemical device. The negative electrode plate (10) comprises: a negative current collector (11), a negative active material layer (12), and an inorganic dielectric layer (13) which are provided in a stacked manner; the negative active material layer (12) comprises opposite first surface (121) and second surface (122), wherein the first surface (121) is disposed away from the negative current collector (11); the inorganic dielectric layer (13) is disposed on the first surface (121) of the negative active material layer (12) and consists of an inorganic dielectric material. The negative electrode plate (10) provided by the application is useful in an electrochemical device, and can result in an electrochemical device having simultaneously excellent safety performance and cycle performance.