Preparation method and application of titanium nitride fiber-enhanced quasi-solid-state electrolyte
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Solution Overview
Problem
Current polymer electrolytes used in solid-state lithium metal batteries suffer from low ionic conductivity, poor lithium ion transference number, and inadequate inhibition of lithium dendrite growth, leading to capacity attenuation, shorter cycle life, and safety hazards.
Innovation Solution
A titanium nitride (TiN) nanofiber-enhanced quasi-solid-state polymer electrolyte (QPE) is developed through a method involving electrospinning and high-temperature calcination, which significantly improves the interaction between the TiN filler and the polymer substrate, enhancing electrochemical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If pure polymer electrolyte is used, then flexibility and processability are improved, but ionic conductivity and lithium ion transference number are reduced
Solution Approach 1:
The patent uses PVDF-HFP polymer as the base material and incorporates TiO2 nanofibers as filler to create a composite electrolyte. The TiO2 nanofibers are prepared via electrospinning and high-temperature calcination, forming a three-dimensional network structure that enhances ionic conductivity while maintaining the polymer's flexibility and processability.
2Reliability
If polymer electrolyte is used, then interface contact with electrode is improved, but lithium dendrite growth inhibition is insufficient
Solution Approach 1:
The patent introduces TiO2 nanofibers with specific surface area and localized electronic properties into the polymer electrolyte. These nanofibers create localized regions with enhanced electron conductivity and specific surface area that selectively inhibit lithium dendrite nucleation and growth at the electrode-electrolyte interface, while maintaining good overall interface contact.
3Strength
If polymer electrolyte with high crystallization is used, then mechanical strength is improved, but ability to disassociate lithium salt is reduced
Solution Approach 1:
The electrospun TiO2 nanofibers form a porous three-dimensional network structure within the polymer electrolyte. This porous structure provides additional pathways for lithium ion transport and increases the surface area for lithium salt disassociation, compensating for the reduced disassociation ability caused by high polymer crystallization while maintaining mechanical integrity.
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 TiN nanofiber-enhanced QPE demonstrates improved ionic conductivity, increased lithium ion transference number, and enhanced inhibition of lithium dendrite growth, resulting in a specific discharge capacity of 164 mAh g−1 at 0.1 C and 105 mAh g−1 at 5 C, with a capacity retention rate of over 95% after 100 cycles.
Implementation Method 1
The TiN nanofiber has high mechanical strength and specific surface area, which increases interaction between the filler and the polymer substrate
Implementation Method 2
The TiN nanofiber has high mechanical strength and specific surface area, which increases interaction between the filler and the polymer substrate
Implementation Method 3
The filler not only increases the electron conductivity of the electrolyte but also reduces the electronic polarization of the electrolyte
Implementation Method 4
Preparation of TiN Nanofiber: Adding, stirring, and dissolving polyvinylpyrrolidone in a mixed solution of anhydrous ethanol and glacial acetic acid, and then adding tetrabutyl titanate and continuing stirring to form a uniform solution as the electrospinning precursor solution
Implementation Method 5
Heating the fiber felt to a calcination temperature in an air atmosphere and then calcining at the calcination temperature to obtain TiO2 nanofiber
Implementation Method 6
Placing the TiO2 nanofiber into a tube furnace and then introducing a mixed gas of NH3 and Ar into the tube furnace. Heating the tube furnace to the calcination temperature to obtain TiN nanofiber
Data Source
AI summary
A preparation method and application of a titanium nitride fiber-enhanced quasi-solid-state electrolyte, which relates to a synthetic method and application of a solid-state electrolyte. The object of the present disclosure is to solve the problem that the existing polymer electrolyte has low ionic conductivity, poor lithium ion transference number, and insufficient inhibition of lithium dendrite growth. The method includes the following steps: 1. preparation of TiN nanofiber, and 2. preparation of electrolyte. The TiN nanofiber-enhanced electrolyte is used as a solid-state electrolyte of lithium ion batteries. The electrolyte material provided by the present disclosure has excellent rate performance, high cycle stability, and long-term cycle life. In the present disclosure, a TiN nanofiber-enhanced quasi-solid-state electrolyte can be obtained.