Lithium Battery Anode Protective Layer Preventing Dendrite Growth
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Solution Overview
Problem
Lithium secondary batteries face issues with electrolyte loss and dendrite growth during repetitive charging/discharging, leading to battery life deterioration and stability concerns.
Innovation Solution
A negative electrode with a protective layer comprising a polymer matrix having a three-dimensional crosslinked network structure, where the polymer matrix includes polystyrene sulfonate or polysilsesquioxane, and contains an electrolyte, inhibiting electrolyte loss and dendrite growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a conventional negative electrode structure is used, then the battery can operate initially, but electrolyte is lost during repetitive charging/discharging leading to battery life deterioration
Solution Approach 1:
A protective layer comprising a polymer matrix is formed on the negative electrode active layer. This thin film structure physically confines the electrolyte within the polymer matrix, preventing electrolyte loss during battery operation while maintaining flexibility for lithium ion transport.
Solution Approach 2:
The protective layer is constructed as a composite material system consisting of a polymer matrix (such as polystyrene sulfonate or polysilsesquioxane) combined with electrolyte. This composite structure provides both mechanical integrity to retain electrolyte and chemical functionality to enable lithium ion conduction, thereby extending battery life.
2Reliability
If a conventional negative electrode structure is used, then the battery can operate, but lithium dendrite grows leading to stability concerns
Solution Approach 1:
The protective layer acts as a thin film barrier that physically constrains lithium ion deposition, preventing the formation of dendritic structures. The polymer matrix provides a uniform interface that guides lithium ion flow, eliminating the conditions that lead to dendrite growth and improving battery stability.
Solution Approach 2:
The protective layer modifies the local environment at the negative electrode surface by changing the physical and chemical parameters such as surface energy, ionic conductivity, and mechanical properties. These parameter changes create favorable conditions for uniform lithium plating/stripping, preventing dendrite formation and enhancing battery reliability.
3Reliability
If a protective layer is added to prevent electrolyte loss and dendrite growth, then battery stability improves, but the device structure becomes more complex
Solution Approach 1:
The protective layer is integrated directly onto the negative electrode active layer, merging the protective function with the electrode structure itself. This eliminates the need for separate protective components and simplifies the overall battery construction while maintaining enhanced stability.
Solution Approach 2:
The polymer matrix protective layer performs multiple functions simultaneously: it retains electrolyte, prevents dendrite growth, enables lithium ion conduction, and provides mechanical support. This multi-functionality reduces the need for additional components, thereby limiting the increase in device complexity while achieving improved battery stability.
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 prevents electrolyte loss and dendrite growth, enhancing battery stability and performance by maintaining electrolyte within the polymer matrix and controlling lithium ion transfer.
Implementation Method 1
a protective layer which comprises a polymer matrix containing electrolyte, on the negative electrode active layer
Implementation Method 2
the polymer matrix having a three dimensional crosslinked network structure of polymer
Data Source
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AI summary
The present invention relates to a negative electrode for lithium secondary battery and a lithium secondary battery including the same. The negative electrode includes a negative electrode active layer comprising lithium, and a protective layer disposed on the negative electrode active layer, wherein the protective layer comprises a polymer matrix having a three dimensional crosslinked network structure of polymer or includes a non-crosslinked linear polymer, and an electrolyte in the polymer matrix in the amount of 100 to 1000 parts by weight based on 100 parts by weight of the polymer matrix. The negative electrode according to the present invention has no concern about loss of electrolyte and the resulting deterioration of battery life characteristics even during the repetitive charging/discharging of the battery and has improved battery stability due to the inhibition of growth of lithium dendrite.