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Seawater electrolysis for green hydrogen production is one of the key technologies for achieving carbon neutrality. However, in anode systems, the chloride ions (Cl−) in seawater will trigger an undesired chlorine evolution reaction (CER) that competes with an oxygen evolution reaction (OER), resulting in inferior OER activity and selectivity. Besides, the corrosive Cl−and its derivative products will corrode anodes during seawater electrolysis, leading to poor stability. Therefore, great efforts have been devoted to developing efficient strategies for chlorine inhibition to improve the activity, selectivity, and stability of anode materials. Herein, focusing on chlorine inhibition, we present a mini review to comprehensively and concisely summarize the recent progress in anode systems for boosting seawater electrolysis. In particular, two strategies of physical and chemical regulation to inhibit Cl−are summarized in some representative cases. Finally, some challenges and future opportunities in anode systems for seawater electrolysis are prospected. This mini review aims to shed light on designing highly efficient anode materials for seawater electrolysis.

Rotational energy is a type of common energy source that can be harvested for supplying low-powered electronic devices. This paper proposes and investigates a novel cam-like dielectric elastomer generator (CDEG) for high-performance rotational energy harvesting. A mushroom-head clamp is designed to form a type of advanced conical dielectric elastomer membranes (DEMs). Moreover, a type of multi-protrusion cam mechanism is designed in the CDEG to effectively convert any external rotational excitation into a linear reciprocating motion, which can be further converted into electricity through the DEMs. First, the operating principle of the system under external rotational excitation is analyzed theoretically by deducing the deformation condition of the DEMs and the electrical output of the system. Second, the prototype is fabricated, and the rotational-to-linear motion conversion rule of its cam-like mechanism and the DEM capacitance calculation approach are validated. The experimental results show that adequate charging time and discharging time of the DEMs, which can be realized through the proposed cam-like mechanisms, are beneficial to the energy harvesting (EH) performance of the system. Third, with the validated theoretical model, numerical simulations are conducted to further study the system dynamics and the influences of important system parameters on the EH performance to provide a guideline for system improvement. Finally, the genetic algorithm is adopted to obtain the optimal system parameters and the corresponding electrical output of the proposed CDEG, demonstrating its superior output power at ultralow rotational frequencies compared with other typical rotational energy harvesters in the literature.

Bearingless motors combine torque and magnetic levitation into a single electric machine. Recent research indicates that this technology has the potential to yield a reliable, oil-free, highly-efficient, and integrated solution for industrial applications if the cost associated with the electric drive can be reduced. This paper investigates power electronic implementations that reduce the required number of inverters, and thereby reducing the drive cost. The paper targets electric machinery for significant power applications, such as compressor systems, which require active actuation in all degrees of freedom (DOF). The paper shows that by implementing the system as a twin bearingless machine configuration, with each machine using a combined winding, the number of inverters (and supporting components) can be reduced by 25% through novel connections of the winding coil groups. Nine reduced-component twin bearingless machine drive configurations are proposed, evaluated, and compared. Power electronic and control implementations are proposed and experimental results demonstrate reduced-component drives levitating a prototype twin machine and controlling machine coil currents identically to the conventional (full-cost) bearingless drive.

The induction machine has proven to be one of the most difficult motor technologies to transform into a bearingless motor due to currents that are induced in the squirrel cage rotor by the suspension field. This paper develops a new rotor for use in a bearingless induction motor to solve this problem. The rotor is described as “pole-specific” because its winding couples to the motor field but not the suspension field. This new structure uses a common end-ring to reduce the rotor’s axial length, solving rotor dynamic challenges present in previous efforts to develop a pole-specific rotor. This paper presents the new rotor concept and leverages traditional cage rotor design theory to develop equivalent circuit models and a theoretical framework that reveals which combinations of poles and slots can be used to implement the new rotor. Experimental results validate the new rotor concept and demonstrate its performance improvement over the classical squirrel cage rotor. A case study is presented of a high performance 50 kW, 30,000 r/min design for an industrial compressor with a modeled efficiency of 96.8%.