Improved NiMH performance by a surface treatment that creates magnetic Ni-clusters

Shen, Yang; Peng, Fei; Kontos, Sofia; Noréus, Dag

doi:10.1016/j.ijhydene.2016.01.145

Cited by 12 publications

(12 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This indicates that a bulk hydroxide interphase formed underneath the needles remains. From Figure 3, the half-cell test shows an optimum in capacity (~240 mAh g −1 ) for the sample with 30 min of sonication, however, the discrepancy is still large when compared to the fresh alloy, which had a capacity around 320 mAh g −1 [5]. This is probably due to a thicker interphase covering the surface as the corrosion-resistance of the alloy is lower.…”

Section: Resultsmentioning

confidence: 94%

“…The surface layer observed on the corroded particles was determined to be oxygen-rich by EDS mapping (Figure 7). This oxygen-rich structure is most likely, as previously shown, made up of rare-earth hydroxides [5]. Cross-sections of the untreated cycled material and the ball-milled material were prepared (Figure 6).…”

Section: Figurementioning

confidence: 89%

“…This protective interphase also holds nickel-containing nano-sized clusters formed during the initial corrosion. The clusters are important for the catalytic activity promoting the making and breaking of O-H bonds during discharge and charge, respectively [5,6].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Upcycling of Spent NiMH Battery Material—Reconditioned Battery Alloys Show Faster Activation and Reaction Kinetics than Pristine Alloys

et al. 2020

Self Cite

View full text Add to dashboard Cite

During formation and cycling of nickel–metal hydride (NiMH cells), surface corrosion on the metal hydride particles forms a porous outer layer of needle-shaped rare-earth hydroxide crystals. Under this layer, a denser but thinner oxidized layer protects the inner metallic part of the MH electrode powder particles. Nano-sized nickel-containing clusters that are assumed to promote the charge and discharge reaction kinetics are also formed here. In this study, mechanical treatments are tested to recycle hydrogen storage alloys from spent NiMH batteries. This removes the outer corroded surface of the alloy particles, while maintaining the catalytic properties of the surface. Scanning electron microscopy images and powder X-ray diffraction measurements show that the corrosion layer can be partly removed by ball milling or sonication, combined with a simple washing procedure. The reconditioned alloy powders exhibit improved high rate properties and activate more quickly than the pristine alloy. This indicates that the protective interphase layer created on the alloy particle during their earlier cycling is rather stable. The larger active surface that is created by the mechanical impact on the surface by the treatments also improves the kinetic properties. Similarly, the mechanical strain during cycling cracks the alloy particles into finer fragments. However, some of these particles form agglomerates, reducing the accessibility for the electrolyte and rendering them inactive. The mechanical treatment also separates the agglomerates and thus further promotes reaction kinetics in the upcycled material. Altogether, this suggests that the MH electrode material can perform better in its second life in a new battery.

show abstract

Section: Resultsmentioning

confidence: 94%

Section: Figurementioning

confidence: 89%

See 1 more Smart Citation

Upcycling of Spent NiMH Battery Material—Reconditioned Battery Alloys Show Faster Activation and Reaction Kinetics than Pristine Alloys

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…These batteries are the earliest advanced rechargeable batteries with low maintenance and high reliability [95], [96]. From 1991 to date, the energy densities of Ni-MH increased from around 55 Wh/kg to about 100 W/kg whereas the power densities have increased from about 200 to 1300 W/kg over the last two decades [10], [97]. Fig.…”

Section: Nickel Metal Hydride Batteries (Ni-mh)mentioning

confidence: 99%

Review of Energy Storage Systems in Regenerative Braking Energy Recovery in DC Electrified Urban Railway Systems: Converter Topologies, Control Methods & Future Prospects

SADIQ¹

2021

Preprint

View full text Add to dashboard Cite

<p>Electrified urban railway systems are large consumers of energy in urban areas and thus, there is a need for energy saving measures in this transportation sector. Recuperation of train’s regenerative braking energy (RBE) is one of the best ways for attaining high levels of energy efficiency in this area. Energy Storage Systems (ESSs) prove to be the most practical and viable solution for maximizing the RBE utilization in urban railway systems. In the existing related reviews of ESSs, few papers covered the review of ESS technologies or converter interface. However, a comprehensive review is needed in this regard. This paper discusses an overview of urban railway electrification, and detail review for the three ESS components – ESS Technologies, Bidirectional DC-DC Converters (BDCs), and Controller Unit. This study concludes that among the storage technologies, supercapacitor ESS appears to be the most suitable followed by Lithium-ion batteries and flywheels. For BDC, cascaded BDC is the most suitable followed by dual active bridge. For control methods, fuzzy logic and artificial intelligent are recommended among other control strategies. Thus, the key contribution of this paper is the comprehensive review and analyses of the ESS’s components in the recovery of RBE in urban railways. </p>

show abstract

“…Among these processes, the alkaline bath is very effective in dissolving the native oxide, so as to form a porous oxide surface with catalytic Ni clusters imbedded [13,[16][17][18][19][20][21][22] and to increase the surface reactive area [23]. In the past, we have used this technique to prepare the alloy for the study of activated surfaces without going through electrochemical formation cycling [24].…”

Section: Introductionmentioning

confidence: 99%

Effects of Alkaline Pre-Etching to Metal Hydride Alloys

Meng¹,

Kim

Hu³

et al. 2017

Batteries

View full text Add to dashboard Cite

Abstract:The responses of one AB 5 , two AB 2 , four A 2 B 7 , and one C14-related body-centered-cubic (BCC) metal hydrides to an alkaline-etch (45% KOH at 110 • C for 2 h) were studied by internal resistance, X-ray diffraction, scanning electron microscope, inductively coupled plasma, and AC impedance measurements. Results show that while the etched rare earth-based AB 5 and A 2 B 7 alloys surfaces are covered with hydroxide/oxide (weight gain), the transition metal-based AB 2 and BCC-C14 alloys surfaces are corroded and leach into electrolyte (weight loss). The C14-predominated AB 2 , La-only A 2 B 7 , and Sm-based A 2 B 7 showed the most reduction in the internal resistance with the alkaline-etch process. Etched A 2 B 7 alloys with high La-contents exhibited the lowest internal resistance and are suggested for use in the high-power application of nickel/metal hydride batteries.

show abstract

Improved NiMH performance by a surface treatment that creates magnetic Ni-clusters

Cited by 12 publications

References 12 publications

Upcycling of Spent NiMH Battery Material—Reconditioned Battery Alloys Show Faster Activation and Reaction Kinetics than Pristine Alloys

Upcycling of Spent NiMH Battery Material—Reconditioned Battery Alloys Show Faster Activation and Reaction Kinetics than Pristine Alloys

Review of Energy Storage Systems in Regenerative Braking Energy Recovery in DC Electrified Urban Railway Systems: Converter Topologies, Control Methods & Future Prospects

Effects of Alkaline Pre-Etching to Metal Hydride Alloys

Contact Info

Product

Resources

About