Graphene enabled percolative nanocomposites with large electrocaloric efficient under low electric fields over a broad temperature range
Abstract
For practical electrocaloric (EC) cooling devices, besides a large electrocaloric effect (ECE), the EC coefficients, e.g., ΔT/ΔE and ΔS/ΔE, where ΔT is the adiabatic temperature change, ΔE is the applied field change, and ΔS is the isothermal entropy change, are equally or even more important. An EC material with a large ECE and large EC coefficients will lead to practical EC cooling devices with high reliability. Here, we investigate a graphene enabled percolative relaxor polymer nanocomposite in order to address the challenge of how to generate a practically usable electrocaloric effect (ECE) under low electric field. We show that, through a proper fabrication process, the nanocomposites can reach a ΔT=5.2K and ΔS=24.8Jkg‑1K‑1 under 40MVm‑1, generating a large electrocaloric coefficients of ΔT/ΔE=0.13×10‑6kmV‑1 and ΔS/ΔE=0.62×10‑6Jmkg‑1K‑1V‑1. The work here indicates the promise of the percolative nanocomposite approach with graphene nanofillers to achieve a highly efficient and large ECE in the EC polymers for practical EC cooling.
- Publication:
-
Nano Energy
- Pub Date:
- April 2016
- DOI:
- 10.1016/j.nanoen.2016.02.026
- Bibcode:
- 2016NEne...22..461Y
- Keywords:
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- Electrocaloric effect;
- Graphene;
- Percolative nanocomposites