Piezovoltaics from PdH

Area of Science:

• Energy science
• Materials science
• Electrochemistry

Background:

• Metal hydrides are crucial in energy applications.
• A pressure gradient can drive hydrogen atom expulsion.
• Piezovoltaic devices, acting as pressure-gradient-driven batteries, separate proton and electron migration.

Purpose of the Study:

• To investigate the piezovoltaic performance of palladium hydride (PdH).
• To explore the use of various proton conductors as electrolytes in PdH piezovoltaic devices.
• To demonstrate a novel method for converting mechanical energy into electrical energy using metal hydrides.

Main Methods:

• Experimental investigation of PdH piezovoltaic performance with different proton conductors.
• Measurement of output current and voltage from a PdH sample.
• X-ray diffraction to observe hydrogen atom escape from the palladium lattice under pressure gradients.

Main Results:

• A piezovoltaic output current of approximately 40 nA and a voltage of around 0.8 V were detected for a 3 μg PdH sample.
• X-ray diffraction confirmed the escape of hydrogen atoms from the palladium lattice due to increasing pressure gradients.
• Established the analogy between piezovoltaics (chemical) and piezoelectricity (physical), similar to batteries and capacitors.

Conclusions:

• Metal hydrides, specifically PdH, exhibit significant piezovoltaic performance.
• This work presents a new pathway for mechanical energy to electrical energy conversion.
• Piezovoltaic devices offer a novel application for metal hydrides in energy science.