Cost-Effective Battery Separators Using Nanofiber Technology

By AZoNano.com Staff Writers

Topics Covered

Introduction
Key Characteristics of Separators
Materials for Battery Separators
Nanofiber Battery Separators
Key Benefits of Elmarco's Technology
About ELMARCO

Introduction

Separators are a key component in all batteries, used for isolating the positive and negative electrodes to avoid electrical short circuits, while allowing ionic charge carriers to be transported rapidly to complete the circuit in the course of the passage of current in an electro-chemical cell (Figure 1).

Figure 1. Structure of a Battery

Key Characteristics of Separators

Battery separators are porous membranes positioned between the electrodes of opposite polarity. They are permeable to ionic flow but avoiding electric contact of the electrodes. They need to be very good electronic insulators with the ability to conduct ions by soaking electrolyte or by intrinsic ionic conductor. They must hinder any processes that negatively affect a battery’s electrochemical energy efficiency.

Materials for Battery Separators

Over the years, many different separators have been employed in batteries. Starting with sausage casing and cedar shingles, separators have been fabricated from cellophane and cellulosic papers to ion exchange membranes, foams, nonwoven fabrics, and microporous flat sheet membranes built from polymeric materials. As battery technology is advancing, separator function is also becoming more demanding and complex.

Nanofiber Battery Separators

Nanofiber battery separators fabricated from PAN, PVDF and copolymer can be used as a replacement for common PE and PP separator membranes. Elmarco’s Nanospider equipment facilitates the production of nonwoven nanofibrous separators, which satisfy the following key performance requirements of a battery separator:

  • Tensile strength - Acceptable for winding machines
  • Chemical stability
  • Porosity - More than 40%
  • Thickness - Dimensional stability
  • Thermal stability - Below 5% shrinkage after 60 min at 90°C in a vacuum
  • Pore size and pore size distribution –Homogeneous pore distribution to eliminate performance loss caused by non-uniform current densities

Key Benefits of Elmarco's Technology

Batteries with superior parameters can be constructed with Elmarco's nanofiber technology. Elmarco's technology facilitates the fabrication of cost-efficient separators through:

  • Higher charge and discharge rate
  • Improved battery life
  • Considerable increase of battery power density
  • Lower polymer material consumption owing to the reduced basis weight of the membrane

About ELMARCO

Elmarco is the industry's first supplier of industrial scale nanofiber production equipment. Partnerships with global industrial leaders and universities form the foundation for success of the company. Elmarco's unique Nanospider™ technology is designed for ease of use, scalability, modularity and flexibility in producing the highest quality nanofibers.

Nanospider™ technology is a patented, needle-free high voltage, free liquid surface electrospinning process. The technology is based upon the discovery, that it is possible to create Taylor Cones and the subsequent flow of material not only from the tip of a capillary, but also from a thin film of a polymer solution.

The technology enabled Elmarco to build industrial scale production equipment with out nozzles, needles or spinnerets.

Nanospider™ technology allows the production of nanofibers from polymers solved in water, acids or bipolar solvents as well as from melted polymers and is suitable for the production of organic and inorganic fibers. This versatile technology is easily adapted to a variety of process parameters for the optimization of the specific properties of the produced nanofibers.

This information has been sourced, reviewed and adapted from materials provided by ELMARCO.

For more information on this source, please visit ELMARCO.

Date Added: Dec 6, 2013 | Updated: Dec 6, 2013
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