Cooperation of a PEM fuel cell and a NiMH battery at various states of its charge in a FCHEV drive

The development of electromobility is focused on the design and implementation of increasingly more effective electric drives. In such a system, apart from energy recovery, it is not possible to recharge the batteries while driving. Electric vehicles equipped with fuel cells and a battery (FCHEV – fuel cell hybrid electric vehicle) in a parallel configuration boast increased energy transfer capabilities. The article presents an energy flow analysis in a parallel hybrid drive system with fuel cells and a battery. The research was carried out on a 30 W vehicle made in 1:10 scale with a NiMH battery and a fuel cell with a proton exchange membrane (PEM). Increasing driving dynamics causes a 29% increase in energy consumption, 43.6% reduction of energy transfer from a fuel cell and a 23% increase of in the energy share intended for battery charging. Continuous operation of the system in full power mode ensures a much greater efficiency of energy transmission to the drive train (95%) compared to the system operating in dynamic driving conditions – 64–75%.

Short-Term Impact of AC Harmonics on Aging of NiMH Batteries for Grid Storage Applications

Batteries in energy storage systems are exposed to electrical noise, such as alternating current (AC) harmonics. While there have been many studies investigating whether Lithium-ion batteries are affected by AC harmonics, such studies on Nickel Metal Hydride (NiMH) batteries are scarce. In this study a 10 Ah, 12 V NiMH battery was tested with three different harmonic current frequency overlays during a single charge/discharge cycle: 50 Hz, 100 Hz, and 1000 Hz. No effect on battery internal temperature or gas pressure was found, indicating that NiMH battery aging is not affected by the tested harmonic AC frequencies. This can reduce the cost of energy storage systems, as no extra filters are needed to safeguard the batteries. Instead, the capacitive properties of the batteries give the possibility to use the battery bank itself as a high pass filter, further reducing system complexity and cost.

Integrated Leaching and Separation of Metals Using Mixtures of Organic Acids and Ionic Liquids

In this work, the aqueous phase diagram for the mixture of the hydrophilic tributyltetradecyl phosphonium ([P44414]Cl) ionic liquid with acetic acid (CH3COOH) is determined, and the temperature dependency of the biphasic region established. Molecular dynamic simulations of the [P44414]Cl + CH3COOH + H2O system indicate that the occurrence of a closed “type 0” biphasic regime is due to a “washing-out” phenomenon upon addition of water, resulting in solvophobic segregation of the [P44414]Cl. The solubility of various metal oxides in the anhydrous [P44414]Cl + CH3COOH system was determined, with the system presenting a good selectivity for CoO. Integration of the separation step was demonstrated through the addition of water, yielding a biphasic regime. Finally, the [P44414]Cl + CH3COOH system was applied to the treatment of real waste, NiMH battery black mass, being shown that it allows an efficient separation of Co(II) from Ni(II), Fe(III) and the lanthanides in a single leaching and separation step.

Life-Cycle Assessment on Nickel-Metal Hydride Battery in Hybrid Vehicles: Comparison between Regenerated and New Battery

To reduce air pollution and avoid petroleum exhaustion problem, many advanced countries, especially Japan installed Hybrid Vehicles (HV). As the use of HV popularizes around the world, there will be a huge amount of End-of-Life HV in the near future, and the proper treatment of these End-of-Life HVs, especially the waste NiMH (Nickel-Metal Hydride) batteries, will become a serious problem. Currently, the recycling of NiMH battery is gaining substantial attention. However, instead of recycling waste NiMH batteries directly, regenerating and reusing a used NiMH battery for a secondhand HV will largely reduce waste battery generation and demand for new NiMH battery. However, the environmental impact of regenerating and reusing a waste NiMH battery was not clear and has not been compared with the situation when using a brand-new NiMH battery. The purpose of this research is to compare the environmental performance (CO2 emission) of regenerated NiMH battery and brand-new NiMH battery in an HV from their production to usage stage and to discuss the validity of using a regenerated NiMH in Japan and in other countries using the Life-Cycle Assessment (LCA) approach. This research analyzed the composition of a NiMH battery and the CO2 emission during the manufacture, transportation, regeneration and usage process of a NiMH battery. The data used in this research was collected from reports and data published by the government of Japan, vehicle makers and previous studies. Original field survey and interview research on battery regeneration operators were also performed. The result showed that there is not a big difference in environmental effect. Moreover, by doing so, a huge amount of resource will be saved from battery manufacturing process while reducing waste generation. It is recommended that waste NiMH battery should be regenerated and reused in HV instead of being recycled directly in the future.