Polyacrylonitrile Separator with Acidic Surface for Lithium Ion Conductivity
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Solution Overview
Problem
Existing energy storage devices with separators made of polymers containing tetrafluoroethylene segments face limitations in improving charge and discharge performance.
Innovation Solution
An energy storage device is developed using a fibrous membrane composed of polyacrylonitrile as a separator, with its surface modified by acidic functional groups or salts, and an electrolyte that can conduct lithium ions, either in liquid, gel, or solid form, to enhance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polymers containing tetrafluoroethylene segments are used as a separator, then the separator provides basic separation function, but the charge and discharge performance of the energy storage device is limited
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition of the separator through copolymerization of acrylonitrile with specific comonomers (acrylic acid, methacrylic acid, itaconic acid, or their salts) in controlled ratios. This changes the functional parameters of the separator to achieve both high ion permeability and electrochemical stability, resolving the contradiction between basic separation function and performance improvement potential
Solution Approach 2:
The patent uses composite materials by creating a copolymer structure that combines acrylonitrile with acid-containing comonomers. This composite approach integrates the benefits of both polymer components: acrylonitrile provides electrochemical stability while the acid-containing comonomer enhances ion permeability and surface properties, thereby improving charge and discharge performance
2Reliability
If the separator material is modified to improve charge and discharge performance, then the battery performance improves, but the manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by incorporating the desired functional groups (acidic groups from comonomers) directly into the polymer chain during the separator manufacturing process itself, rather than requiring subsequent surface modification or treatment steps. This preliminary incorporation of functional properties simplifies the overall manufacturing process while achieving improved battery 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 modified separator improves battery performance and cycle life, demonstrating superior ionic conductivity and capacitance maintenance rates compared to traditional separators.
Implementation Method 1
a surface of the fibrous membrane is modified by an acidic functional group or a salt thereof
Implementation Method 2
the separator is a fibrous membrane composed of polyacrylonitrile, and a surface of the fibrous membrane is modified by an acidic functional group or a salt thereof
Implementation Method 3
an electrolyte, which is disposed between the anode and the cathode, and cladded on the separator; wherein, the separator is a fibrous membrane composed of polyacrylonitrile
Data Source
AI summary
The disclosure provides an energy storage device, comprising: an anode; a cathode; a separator, which is located between the anode and the cathode; an electrolyte, which is disposed between the anode and the cathode, and cladded on the separator; wherein, the separator is a fibrous membrane composed of polyacrylonitrile, and a surface of the fibrous membrane is modified by an acidic functional group or a salt thereof. The energy storage device of the disclosure can be applied to the technical field of lithium batteries.