Functionalized Separator Coating for Lithium Dendrite Inhibition
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Solution Overview
Problem
Lithium metal batteries are prone to lithium dendrite formation during charging, leading to reduced coulombic efficiency, shortened cycle life, and safety risks such as internal short circuits, explosions, and fires.
Innovation Solution
A functionalized separator with a functional film layer containing inorganic particles that can reversibly react with metal lithium to form a lithium alloy, inhibiting dendrite growth and improving lithium ion deposition/dissolution behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional separator is used in lithium metal batteries, then the battery structure is simple, but lithium dendrites form during charging leading to reduced coulombic efficiency and safety risks
Solution Approach 1:
The separator is constructed as a composite material system consisting of a porous substrate layer and a functional film layer. The functional film layer contains inorganic particles (such as silicon, germanium, or their oxides) that can reversibly react with lithium to form lithium alloys. This composite structure enables the separator to actively manage lithium ion deposition and inhibit dendrite formation, thereby improving coulombic efficiency and safety without excessive complexity
Solution Approach 2:
The separator utilizes a porous substrate layer with controlled pore structure to facilitate lithium ion transport. The porous structure allows efficient ion conduction while the added functional film layer with inorganic particles provides dendrite inhibition. The porosity is optimized to balance ion transport efficiency and structural integrity, preventing dendrite penetration while maintaining good electrochemical performance
2Object-affected harmful factors
If inorganic particles are added to the separator to inhibit dendrites, then dendrite growth is suppressed, but the manufacturing process becomes more complex
Solution Approach 1:
The inorganic particles are pre-dispersed into a slurry solution containing binder and solvent before being coated onto the porous substrate. This preliminary preparation of the functional slurry ensures uniform distribution of inorganic particles, simplifying the subsequent coating and drying processes. The pre-mixed slurry approach avoids complex in-situ particle deposition techniques and enables straightforward manufacturing
Solution Approach 2:
The invention optimizes key parameters including the weight ratio of inorganic particles (1-50 wt%), binder (50-90 wt%), and solvent (10-50 wt%) to achieve effective dendrite inhibition. The inorganic particle size is controlled within 1-10 μm, and the functional film layer thickness is maintained at 1-20 μm. These parameter optimizations ensure effective performance while maintaining manufacturability through standard coating and drying processes
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 functionalized separator enhances the initial coulombic efficiency, cycle performance, and safety of lithium metal batteries by preventing dendrite formation and improving lithium ion reversibility.
Implementation Method 1
the inorganic particles which are able to reversibly react with metal lithium to form a lithium alloy
Implementation Method 2
the inorganic particles and the metal lithium, under the action of the electrolyte solution, will react reversibly to form a lithium alloy
Implementation Method 3
may effectively inhibit the growth of dendrites on lithium metal electrodes
Implementation Method 4
may adjust and control the deposition/dissolution behavior of lithium ions
Implementation Method 5
the polymer coating layer comprises a group that is reversibly bonded with lithium ions
Implementation Method 6
the coating layer may better inhibit the volume change of the lithium alloy during charging and discharging
Implementation Method 7
the group in the coating layer may form chemical bond in suit with lithium ions, wherein the chemical bond may serve as a channel for transmitting lithium ions
Data Source
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AI summary
The present application discloses a functionalized separator, a method for preparing the same, a lithium metal battery, and a device comprising the lithium metal battery. The functionalized separator comprises a porous substrate and a functional film layer provided on at least one side of the porous substrate, wherein the functional film layer comprises inorganic particles which are able to reversibly react with metal lithium to form a lithium alloy.