Lithium Negative Electrode Protective Layer for Stable Deposition
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Solution Overview
Problem
Lithium metal batteries face issues with electrolyte decomposition, leading to reduced coulomb efficiency and shortened cycle life due to lithium dendrite formation and electrolyte depletion, posing safety risks such as fire or explosion.
Innovation Solution
A negative electrode for lithium rechargeable batteries featuring a protective layer composed of a gel polymer electrolyte and lithium-ion conductive nano particles, with specific lithium-ion binding energies and concentration gradients, forms a space charge layer to minimize electrolyte decomposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If lithium metal is used as the negative electrode to achieve high capacity and high energy density, then the theoretical capacity and gravimetric energy density are improved, but lithium dendrite formation and electrolyte decomposition occur leading to reduced coulomb efficiency and shortened cycle life
Solution Approach 1:
A protective layer comprising a gel polymer electrolyte and lithium-ion conductive nanoparticle is introduced as an intermediary between the lithium metal negative electrode and the battery electrolyte. This protective layer mediates the interaction by providing a stable interface that prevents direct contact between the reactive lithium metal and the electrolyte, thereby suppressing electrolyte decomposition and lithium dendrite formation while maintaining high lithium-ion conductivity for sustained cycle life
Solution Approach 2:
The protective layer is constructed as a composite material system combining a gel polymer electrolyte matrix with dispersed lithium-ion conductive nanoparticles. The gel polymer electrolyte provides mechanical stability and ion transport pathways, while the lithium-ion conductive nanoparticles enhance local lithium-ion conductivity and promote uniform lithium deposition. This composite structure achieves both high energy density compatibility and improved reliability by simultaneously addressing electrolyte decomposition and dendrite formation issues
2Duration of action of stationary object
If a protective layer is introduced to reduce electrolyte decomposition and improve cycle life, then the battery lifespan is improved, but the device complexity increases
Solution Approach 1:
The protective layer is designed as a thin film structure with controlled thickness ranging from 1 to 20 micrometers. This thin film approach provides the necessary protective functions (suppressing electrolyte decomposition, preventing dendrite formation) while minimizing the additional volume and mass introduced into the battery system. The gel polymer electrolyte matrix provides flexibility and conformability to the underlying lithium metal electrode surface, ensuring complete coverage without requiring complex structural support
Solution Approach 2:
The protective layer merges multiple functions into a single integrated component: it serves as both a protective barrier against electrolyte decomposition and a lithium-ion conductive pathway for electrochemical reactions. By combining the gel polymer electrolyte (providing mechanical stability and ion transport) with lithium-ion conductive nanoparticles (enhancing local conductivity and uniform deposition), the design achieves multiple protective functions without requiring separate layers for each function, thereby limiting the increase in device complexity
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 protective layer reduces electrolyte decomposition, enhancing the battery's lifespan and safety by maintaining stable lithium deposition and reducing anion consumption.
Implementation Method 1
the gel polymer electrolyte and lithium-ion conductive nanoparticle form a space charge layer, minimizing electrolyte decomposition
Implementation Method 2
the gel polymer electrolyte and lithium-ion conductive nanoparticle form a space charge layer, minimizing electrolyte decomposition
Implementation Method 3
the protective layer comprises a gel polymer electrolyte and a lithium-ion conductive nanoparticle, wherein the gel polymer electrolyte comprises a lithium-ion, an anion, an organic solvent, and a polymer, and a lithium-ion binding energy of the anion is greater than that of the organic solvent
Implementation Method 4
reduces electrolyte decomposition, enhancing the battery's lifespan and safety by maintaining stable lithium deposition and reducing anion consumption
Data Source
AI summary
The present disclosure relates to a negative electrode for lithium rechargeable battery, comprising: a current collector; a lithium-based negative electrode active material layer positioned on the current collector; and a protective layer positioned on the lithium-based negative electrode active material layer, wherein, the protective layer comprises a gel polymer electrolyte and a lithium-ion conductive nano particle, the gel polymer electrolyte comprises a lithium-ion derived from lithium salt, an anion, an organic solvent, and a polymer, and a lithium-ion binding energy of the anion is greater than that of the organic solvent.