Alkaline Cell Separator Pore Structure for Thin Wrap Isolation
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Solution Overview
Problem
Conventional alkaline electrochemical cells face challenges with separator thickness and volume occupancy, leading to decreased space for active ingredients due to the need for multiple wraps of non-woven separator sheets, which can result in anode to cathode electrical shorting and inefficient electrolyte transport.
Innovation Solution
A separator with improved pore size and air permeability, made from alkaline-resistant, ion-permeable, non-conductive materials such as polymeric fibers, is used to reduce the number of wraps, allowing for a thinner design that maximizes electrolyte transport and minimizes shorting risks, while maintaining mechanical strength and chemical resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple wraps of non-woven separator sheets are used, then electrical shorting between anode and cathode is prevented, but volume occupancy increases and space for active ingredients decreases
Solution Approach 1:
The patent employs a porous separator material with optimized pore size distribution that allows efficient ion transport while maintaining electrical insulation. The porous structure enables the separator to achieve effective separation with reduced thickness, preventing electrical shorting between electrodes while minimizing volume occupancy and maximizing space for active ingredients.
Solution Approach 2:
The patent modifies key parameters of the separator including thickness, pore size, and porosity to optimize performance. By changing these parameters, the separator achieves effective electrical isolation with fewer wraps or reduced thickness, thereby reducing volume occupancy while maintaining reliability in preventing electrical shorting.
2Volume of stationary object
If separator thickness is reduced, then space for active ingredients increases, but mechanical strength and chemical resistance may deteriorate
Solution Approach 1:
The patent utilizes composite separator materials that combine multiple components with complementary properties. This composite structure provides enhanced mechanical strength and chemical resistance even at reduced thickness, allowing the separator to maintain integrity and performance while maximizing space for active ingredients.
Solution Approach 2:
The optimized porous structure of the separator provides both mechanical support and chemical stability. The controlled pore architecture distributes stress and resists degradation, enabling the thin separator to maintain adequate mechanical strength and chemical resistance while reducing overall thickness to increase space for active ingredients.
3Ease of manufacture
If non-woven separator sheets are used, then manufacturing is simplified, but electrolyte transport efficiency is reduced
Solution Approach 1:
The patent employs a porous separator with optimized pore size, porosity, and interconnectivity that significantly enhances electrolyte transport efficiency. The improved porous structure facilitates faster and more efficient ion movement through the separator, increasing productivity while maintaining ease of manufacture through established porous material fabrication techniques.
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 improved separator design enhances cell performance by reducing volume occupancy, preventing short-circuiting, and optimizing electrolyte transport, leading to superior high-rate discharge capabilities and extended storage performance at high temperatures.
Implementation Method 1
a separator made from alkaline-resistant, ion-permeable, non-conductive materials
Implementation Method 2
a separator made from alkaline-resistant, ion-permeable, non-conductive materials
Data Source
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AI summary
An alkaline electrochemical cell includes a cathode; a gelled anode having an anode active material and an electrolyte; and a separator disposed between the cathode and the anode; wherein the separator includes a non-conductive, porous material having a mean pore size of about 1 micron to about 5 microns, a maximum pore size of about 19 microns, and an air permeability of about 0.5 cc/cm2/s to about 3.8 cc/cm2/s at 125 Pa.