Recently, energy harvesting through the means of piezoelectric transducer technology has increasingly attracted the attention of engineers and scientists in producing/generating electricity for human consumption. However, understanding of piezoelectric materials for application in piezoelectric transducer devices in energy harvesting remains important in today’s energy systems engineering. Thus, the present review study is centered on piezoelectric materials for a better understanding of the properties of different piezoelectric materials (ceramic) when placed under mechanical stress or vibration and electrical field during energy harvesting using transducer devices. With the available literature, lead zirconate titanate materials showed to be the most common piezoelectric material with a high energy-generating performance but possessed more mechanical failure and also compromised in a harsh environment compared to lead-free piezoelectric materials. As such, the authors conclude that lead-free piezoelectric materials, such as zinc oxide and barium titanate, remain the best conducive piezoelectric material over lead zirconate titanate, which basically affects the human environment due to its toxicity. Thus, to widen the use of lead-free piezoelectric materials in energy harvesting, owing to their improved properties and environment-friendly nature, the authors recommend further enhancement of the lead-free piezoelectric material properties via nanodielectric filler incorporations using the spark plasma sintering technique.
Energy is a requisite factor for technological advancement and the economic development of any society. Currently, global energy demand and supply largely rely on fossil fuels. The use of fossil fuels as a source of energy has caused severe environmental pollution and global warming. To salvage the dire situation, research effort is geared toward the utilization of clean, renewable and sustainable energy sources and the hydrogen energy economy is among the most preferred choices. Hydrogen energy economy, which includes hydrogen production, storage and conversion has gained wide consideration as an ecofriendly future energy solution with a fuel cell as its conversion device. Fuel cells, especially, the proton exchange membrane category, present a promising technology that converts hydrogen directly into electricity with great efficiency and no hazardous emissions. Unfortunately, the current generation of proton exchange membrane fuel cells faces some drawbacks that prevent them from large-scale market adoption. These challenges include the high costs and durability concerns of catalyst materials. The main source of high cost in fuel cells is the platinum catalyst used in the electrodes, particularly at the cathode where the sluggish oxygen reduction reaction kinetics require high loading of precious metals. Many research efforts on proton exchange membrane fuel cells are directed to reduce the device cost by reducing or completely replacing the platinum metal loading using alternative low-cost materials with “platinum-like” catalytic behaviour while maintaining high power performance and durability. Consequently, this review attempts to highlight recent research efforts to replace platinum and carbon support with other cost-effective and durable materials in proton exchange membrane fuel cell electrocatalysts. Overview of promising materials such as alloy-based (binary, ternary, quaternary and high-entropy alloys), single atom and metal-free electrocatalysts were discussed, as the research areas are still in their infancy and have many open questions that need to be answered to gain insight into their intrinsic requirements that will inform the recommendation for outlook in selecting them as electrocatalysts for oxygen reduction reaction in proton exchange membrane fuel cell.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.