Synopsis: Plastic Capacitors

Calculations show that combining polymers can improve their dielectic properties and reveal the atomic rearrangements that make this possible.
Synopsis figure
APS/V. Ranjan et al., Phys. Rev. Lett. (2012)

One of the biggest speed bumps hindering widespread adoption of electric vehicles is energy storage: conventional liquid fuels offer a stored energy per unit weight that is hard to beat. The two current approaches to overcoming this limitation are batteries, which use a chemical reaction to generate electricity, or capacitors, which directly store electricity then discharge it when needed. Capacitors take the lead in applications requiring quick delivery of energy. In essence, capacitors are made from two metal surfaces separated by a dielectric; the capacitance can be improved by bringing the surfaces closer together and by using a separator with high dielectric permittivity.

Computer simulations reported in Physical Review Letters by Vivek Ranjan of North Carolina State University, Raleigh, and colleagues predict that mixing a ferroelectric polymer with a pinch of another polymer could yield a sevenfold increase in stored energy compared to the pure dielectric. The calculations offer insights at the molecular level about how this occurs, showing the polymer atoms collectively rearrange from a nonpolar to polar state. Transition paths uncovered by the work have low activation energies and are accessible at technologically reasonable temperatures. The results point the way toward research into creating such optimized polymer dielectrics, which would make capacitive systems roadworthy for powering electric vehicles. – David Voss


Features

More Features »

Announcements

More Announcements »

Subject Areas

Materials ScienceEnergy Research

Previous Synopsis

Nanophysics

Graphene Nanoribbons Zip Up

Read More »

Next Synopsis

Superconductivity

Universal Pairing Symmetry

Read More »

Related Articles

Viewpoint: How to Make Devices with Weyl Materials
Materials Science

Viewpoint: How to Make Devices with Weyl Materials

Weyl semimetals could be used to build a range of electronic devices, from superlenses for scanning tunneling microscopes to transistors. Read More »

Viewpoint: Relaxation is a Two-Step Process for Metallic Glasses
Materials Science

Viewpoint: Relaxation is a Two-Step Process for Metallic Glasses

Measurements of several metallic glasses under strain reveal that the materials relieve stress through a two-step process that has previously been seen only in “softer” glasses. Read More »

Synopsis: Protons in the Fast Lane
Energy Research

Synopsis: Protons in the Fast Lane

A proposed graphene-based material could offer speedy transport of protons without the need for water. Read More »

More Articles