From the paper: "In electrocaloric devices, electric fields of ≈200 MV m^−1 are common (more than 50 times as large as the dielectric strength of air) and can o

From the paper: "In electrocaloric devices, electric fields of ≈200 MV m^−1 are common (more than 50 times as large as the dielectric strength of air) and can only be generated by applying voltages across micrometer-sized films in the kilovolt range. ... In the ionocaloric device, the applied field is ~0.22 V, which is relatively modest. ... For additional perspective, some high-efficiency aqueous vanadium redox flow batteries operate at 800 mA cm^−2; the ionocaloric device operated at ≈0.5 mA cm^−2 for its highest-efficiency results. If, for example, it operated at 800 mA cm^−2, like in the aqueous system, the cooling power output would be equal to 9.2 kW L^−1." It's fairly common for articles like the one linked to be written by the lab's communications department, who may or may not be familiar with the subject at hand.