Electrocaloric cooling prototype using lead-free barium titanate multilayer capacitors and heat transfer fluid motion

In this paper, we describe the realisation and the testing of an electrocaloric effect based refrigeration prototype. The prototype makes use of Active Electrocaloric Regenerator (AER) made of commercially available MultiLayer ceramics and exploits the oscillating motion of a heat transfer fluid in a thermodynamic refrigeration cycle. The setup allows the adjustment of various parameters and the effect of the frequency of the cycle as well as the volume displaced of the heat transfer fluid has been evidenced. An amplification regenerative factor of 1.25 has been reached, comparable and slightly higher to those of previously proposed electrocaloric refrigerator prototypes.

Energy-storage performance of NaNbO3 based multilayered capacitors

Energy-storage performances of NaNbO3 system were effectively enhanced by composition engineering inducing relaxor behavior and grain refinement. Excellent Wrec = 3.7 J cm−3 and η = 82.1% were achieved in the NN-0.04CZ-0.16BNT multilayer capacitors.

Composition and strain engineered AgNbO3-based multilayer capacitors for ultra-high energy storage capacity

With strain engineer and MnO2 addition, an ultra-high energy-storage density Wrec = 7.9 J cm−3 and efficiency η = 71% were achieved in Ag(Nb0.85Ta0.15)O3 + 0.25 wt% MnO2 multilayer capacitors.

Giant temperature span in electrocaloric regenerator

Cooling devices based on caloric materials have emerged as promising candidates to become the next generation of coolers. Several electrocaloric (EC) heat exchangers have been proposed that use different mechanisms and working principles. However, a prototype that demonstrates a competitive temperature span has been missing. We developed a parallel-plate active EC regenerator based on lead scandium tantalate multilayer capacitors. After optimizing the structural design by using finite element modeling for guidance and to considerably improve insulation, we measured a maximum temperature span of 13.0 kelvin. This temperature span breaks a crucial barrier and confirms that EC materials are promising candidates for cooling applications.

A review on the development of lead-free ferroelectric energy-storage ceramics and multilayer capacitors

Typical lead-free energy storage systems and their performances for dielectric and multilayer capacitors over the last decade.

Fatigue resistant lead-free multilayer ceramic capacitors with ultrahigh energy density

Electrical homogeneity is vital in optimising energy storage performance in BiFeO3–BaTiO3–xBi(Li0.5Nb0.5)O3 ceramic multilayer capacitors, giving rise to high recoverable energy density ∼13.8 J cm−3 under electric field ∼950 kV cm−1 and fatigue resistance behaviour.

Una nueva topología de bajo costo para microinversores

In recent years, the implementation of solar energy facilities has grown, as it is considered an environmentally friendly way to produce electricity. Solar energy can be exploited under different configurations or connection schemes. The most useful connection schemes are the string connection, the power optimizers and the microinverters. Microinverters have a wide advantage compared to the other schemes due to their ability to take advantage of solar energy under different environmental conditions, such as partial shading, temperature and irradiation. The implementation of microinverters has been slowed down because of its high cost and reduced lifetime. In general, the design of microinverters commonly includes elements such as transistors, electrolytic capacitors, sensors and a microcontroller. Electrolytic capacitors are commonly used as decoupling stages, even though they present a lower lifetime due to high frequencies of operation and current rises. In this paper, a new microinverter topology is presented, it uses a low-cost array of multilayer capacitors to filter high frequencies and get a low-cost topology.