Hydride Batteries Research Articles

Strategy of manipulating La/Ce ratio to develop metal hydride electrode with excellent capacity even at −40 °C

Metal hydride electrodes have been widely used in Ni/MH batteries, but their low-temperature discharge (LTD) performance restricts practical application. Herein, we propose a facile strategy for tuning the La/Ce ratio to prepare metal hydride electrodes for ultra-low-temperature Ni/MH batteries. The enthalpy shifts in the positive direction with a decrease in the La/Ce ratio and the thermodynamic stability decreases. Moreover, the resultant enhanced charge transfer and proton diffusion endows the electrode with impressive kinetics at −40 °C. One novel candidate, namely, La0.55Ce0.37M electrode presents the highest reported capacity of 317.3 mAh g−1 (0.2C) and the highest discharge specific capacity of 27.2 mAh g−1 (1C) even at −40 °C. A commercial-grade AAA nickel-metal hydride battery concomitantly presents the specific capacity of 71 and 456 mAh at a large current of 1000 mA at −40 and −20 °C, respectively. The excellent LTD performance indicates the suitability of this strategy for developing advanced ultra-low-temperature Ni/MH batteries.

Grid-Grade Rechargeable Batterie and Predication in Future

China is in a period of the energy transition; more renewable energy is used to replace coal which has caused more and more environmental issues. Researches on energy storage play a significant role in the government’s future sustainable development plans. In this article, four types of rechargeable batteries’ characteristics will be explored and their applications for grid-scale energy storage. The Lithium-ion battery is the most well-established with the less exploring room one. Then Nickel-metal hydride battery, due to the complexity of its reaction condition and electrode materials, still retains room for exploration after decades of development. Mn-Cu battery and Mn-H battery have the shortest development cycle and are mostly still in the experimental research stage. The rechargeable battery is one of the most promising energy storage technologies in the future, but there are many kinds of rechargeable batteries, only part of which can be applied to hydropower storage. In this article, four types of rechargeable batteries are listed in different development stages. By analyzing and comparing their performance, the feasibility of grid-level energy storage is summarized, and the future development direction of them is predicted.

A Molten-Salt Battery for Seasonal Energy Storage

Cost-competitive renewable energy sources, such as wind and solar energy, are more rapidly replacing fossil fuels for power generation. As their integration into the power grid increases, the inherent intermittency exposes a great challenge in maintaining the grid stability. Therefore, the development of low-cost energy storage technology suitable for large-scale manufacturing is essential for the further deployment of renewable energy. We noticed that renewable electricity production usually follows predictable seasonal trends. For example, the longer daylight in summers corresponds to more solar power generated. If any seasonal excess can be efficiently stored and redistributed in times of needs, a power grid based on 100% renewable energy is more feasible. Unfortunately, current rechargeable battery technologies have not been optimized for seasonal storage, as the self-discharge rate ranges from approximately 3–5% for lithium-ion batteries to almost 30% for nickel metal hydride batteries in the first month.In this presentation, we will demonstrate the concept of a rechargeable molten-salt battery with earth-abundant elements and simple construction that preserve the stored energy for long periods of time. Due to its unique operating mechanism, this battery can discharge most of its stored capacity (> 90%) after a period of 1 to 8 weeks. This approach brings new possibilities to seasonal energy storage and helps the grid to overcome short supply during seasonal fluctuations.

(Digital Presentation) Electrochemical Synthesis of Highly Crystalline γ-NiOOH and Its Bifunctional Electrocatalytic Activity Towards Oxygen Evolution and Reduction Reactions in Alkaline Solutions

Nickel (oxy)hydroxides are widely used as cathode materials in alkaline rechargeable batteries, including NiOOH-Cd, NiOOH-Zn and Ni-metal hydride batteries. NiOOH is a 2D-layered compound, known to exist in three different polymorphs α, β and γ. Compared with β-NiOOH, γ-NiOOH has a higher theoretical specific capacity and a lower self-discharge rate. However, when using a battery-grade Ni(OH)2, the β-NiOOH is mainly formed, which may transform to γ-NiOOH in the long run. Batteries based on β-NiOOH have poor life cycling and suffer from volume expansion. Therefore, γ-NiOOH is a desirable electrode material which can also be used in the next-generation high-capacity metal-air batteries due to its excellent electrocatalytic activity towards oxygen evolution reaction (OER).In this presentation, we will report a new synthesis method of γ-NiOOH, in which only γ-phase is formed. The method is based on in-situ electrochemical transformation of a two-dimensional nickel chelate polymer in a carbon matrix in an alkaline electrolyte. γ-NiOOH prepared in this way is highly crystalline and has an excellent catalytic activity towards OER with overpotential of 390 mV at 12 mA/cm2. In addition, it can also catalyze oxygen reduction reaction (ORR), with an onset potential of 0.81 V vs. RHE in 1 M KOH.AcknowledgementsThe authors would like to thank Japan Society for Promotion of Science under the JSPS KAKENHI Grant Number JP 20K05689 for financial supports.

Efficient Recovery of Rare Earth Elements and Zinc from Spent Ni-Metal Hydride Batteries: Statistical Studies.

Considering how important rare earth elements (REEs) are for many different industries, it is important to separate them from other elements. An extractant that binds to REEs inexpensively and selectively even in the presence of interfering ions can be used to develop a useful separation method. This work was designed to recover REEs from spent nickel–metal hydride batteries using ammonium sulfate. The chemical composition of the Ni–MH batteries was examined. The operating leaching conditions of REE extraction from black powder were experimentally optimized. The optimal conditions for the dissolution of approximately 99.98% of REEs and almost all zinc were attained through use of a 300 g/L (NH4)2SO4 concentration after 180 min of leaching time and a 1:3 solid/liquid phase ratio at 120 °C. The kinetic data fit the chemical control model. The separation of total REEs and zinc was conducted under traditional conditions to produce both metal values in marketable forms. The work then shifted to separate cerium as an individual REE through acid baking with HCl, thus leaving pure cerium behind.

Dry chlorination of spent nickel metal hydride battery waste for water leaching of battery metals and rare earth elements

An efficient leaching process was developed for nickel, cobalt, and the rare earth elements (REEs) from spent nickel metal hydride (NiMH) battery waste. The process involves dry chlorination with ammonium chloride in low temperature to produce water-soluble chlorinated compounds, followed by simple water leaching. The factors affecting the conversion and solubilization were studied, including the amount of ammonium chloride, residence time and temperature in dry chlorination, and solid to liquid ratio, time and temperature in water leaching. As a result, the dry chlorination process was found to produce ammonium and chloride containing products, depending on the temperature of the process: ammonium metal chlorides were produced in temperatures of 250–300 ℃, while increasing the temperature to 350 ℃ resulted in formation of metal chlorides. Overall, highest metal recoveries were achieved during 60 min residence time at a temperature of 350 °C, where ammonium is no longer present and ammonium metal chlorides and metal chlorides have formed. Water leaching was found to proceed rapidly, especially for REEs, and yields of 87% for Ni, 98% for Co, 94% for Ce, and 96% for La were attained during 60 min of leaching in room temperature. This study introduces a process, which is considered as an environmentally more benign alternative to traditional mineral acid leaching, resulting in high metal leaching efficiencies with neutral leachates, requiring no chemical-intensive neutralization steps in the following processing.

Electrochemical study of the LaFe0.8Ni0.2O3 perovskite-type oxide used as anode in nickel-metal hydride batteries

The electrochemical hydrogen storage properties of the LaFe0.8Ni0.2O3 perovskite-type oxide used as the negative electrode in the nickel metal-hydride battery have been studied in this work. This oxide has been synthesized by the sol-gel method and its structure and electrochemical properties are systematically studied. X-ray diffraction (XRD) analysis showed that the LaFe0.8Ni0.2O3 perovskite-type oxide consists of a single phase and crystallizes in the orthorhombic space group with the Pnma space group. The electrochemical cycling properties of the LaFe0.8Ni0.2O3 negative electrode were carried out at 25 °C using the galvanostatic charging and discharging polarization method for 50 cycles. An optimization of the experimental parameters were carried out in order to optimize the charging potential, the charging and discharging current and the charging time. The best properties were observed for the optimal parameters, such as a discharge potential of 0.4V, a charge and discharge current of 4.44 mA g−1 and a charge time of 5 h.

Recovery of rare earth elements from spent NiMH batteries using subcritical water extraction with citric acid

Spent nickel-metal hydride (NiMH) batteries contain high concentrations of rare earth elements (REEs), nickel (Ni), and cobalt (Co). Subcritical water extraction (SWE) process with citric acid as the leaching reagent was applied to spent NiMH batteries. The effects of acid concentration, solid to liquid ratio (S/L), reaction time, and reaction temperature were examined. Leaching efficiency increased with increasing acid concentration, reaction time and temperature, and decreased as S/L increased. Total of 90.85% of lanthanum (La), 88.84% of cerium (Ce), 90.85% of neodymium (Nd), 90.70% of Ni, and 91.62% of Co were leached out using 2.0 N of citric acid, S/L of 10 g/L, at 150 °C in 5 min. Selective precipitation of REEs was induced by the addition of diluted waste phosphoric acid (H3PO4) to the leaching solutions. At [H3PO4]:[REEs] of 10:1, pH 2.0, and 65 °C, 99.3% of La, 98.8% of Ce, and 99.0% of Nd were precipitated, which correspond to overall recovery of 90.2% of La, 87.8% of Ce, and 89.8% of Nd. The results showed that SWE using citric acid followed by selective precipitation with H3PO4 could effectively recover REEs from spent NiMH batteries.

Lithium-Ion Battery Technologies for Electric Mobility – State-of-the-Art Scenario

Rechargeable batteries are an integral part of all types of electric vehicles (EVs). Batteries must contain higher energy-power densities and longer cycle life for an EV system. Lead-acid batteries, Nickel-metal hydride batteries, and Lithium-ion batteries (LIBs) have been employed as charge storage in EV systems to date. Lead-acid batteries and Nickel-metal hydride batteries were deployed in EVs by General Motors in 1996. However, the low specific energy in Lead-acid batteries (34 Whkg-1) and high self-discharge (12.5% per day at r.t.) in Nickel-metal hydride batteries have marked these batteries obsolete in EV applications. LIBs currently occupy most of the EV market because of their high specific power (~130-220 Whkg-1) and a low selfdischarge rate (~5% per month). The current technological maturity and mass production in LIBs have reduced the overall battery cost by ~98% in the last three decades, reaching an average value of $140 kWh-1 in 2021. Although a game-changer in battery technologies, LIBs encounter various challenges: high cost, low safety, less reliability, and immature infrastructure despite environmental benignness. Overcharging and overheating of LIBs can cause thermal runway leading to fire hazards or explosion. Declining Liresources also raise concerns regarding the reliability and shelf-life of LIB technology. Hence, a critical assessment of Li-ion chemistries is essential to comprehend the potential of LIBs in electric mobilities and to realize the prospects in EVs.

Recovery of Lanthanum from Aqueous Solutions by Crystallization as Lanthanum Sodium Sulfate Double Salt

The recovery of rare earth elements from spent nickel-metal hydride batteries by hydrometallurgical processing has become increasingly important in recent years. The present work investigated the effect of temperature, systems of adding the reactant, the molar ratio of sodium and lanthanum, and the initial concentration of six sulfate impurities (Ni, Co, Al, Mn, Fe, and Zn) on the crystallization of the monohydrate of sodium lanthanum sulfate double salt (NaLa(SO4)2·H2O) crystals from synthetic leachate solutions. The sodium sulfate reactant was added as an acidic solution by pumping or batchwise as a solid anhydrate salt to a pregnant lanthanum sulfate solution. Compared to precipitation with acidic sodium sulfate solution, precipitation with solid sodium sulfate yielded smaller single crystals, a greater tendency to form aggregates, and lower crystal purity. The lowest overall impurity and highest lanthanum quantity in crystals were obtained by semi-batch reactant adding performance of Na2SO4 solution at 70°C with Na/La molar ratio of 3. Real-time monitoring of the count rates of different chord length fractions clearly showed the influence of crystallization temperature on the precipitation kinetics.

The Hazards of Electric Car Batteries and Their Recycling

In recent years, under the double pressure of energy exhaustion and environmental deterioration, the development of electric vehicles has become the major development trend of the automotive industry in the future. This paper discusses the problem of abandoned batteries caused by the limited life of a large number of batteries with the prosperity of new energy vehicle industry. This paper lists and analyzes the different characteristics of batteries commonly used by three new energy vehicles in the market :(1) lead-acid batteries will not leak in the use process due to tight sealing, but their use cycle is very short. (2) The production of nickel metal hydride battery is relatively mature, its production cost is low, and compared with lithium electronic battery is safer. (3) Lithium-ion batteries are made of non-toxic materials, which makes them known as “green batteries”. However, they are expensive to make and have poor compatibility with other batteries. Because discarded batteries pose a threat to human health and environmental sustainability, lithium-ion batteries may overheat and fire when exposed to high temperatures or when penetrated, releasing carbon monoxide and hydrogen cyanide that can be very harmful to human health. In addition, waste batteries will also cause water pollution and inhibit the growth and reproduction of aquatic organisms and other potential dangers. Therefore, it is necessary to recycle it efficiently. This paper then introduces the advantages of three recycling methods: step utilization and recovery, ultrasonic recovery and sodium ion battery. These recycling methods can maximize the reuse efficiency of waste batteries. This paper expects to find a better way to recycle waste batteries to solve the potential problems of improper disposal of waste batteries and reduce the environmental hazards of waste batteries.

Hydrides compounds for electrochemical applications

Hydrides have been used since a long time for solid-state hydrogen storage and electrochemical nickel-metal hydride batteries. Besides these applications, growing attention has been devoted to their development as anode materials, as well as solid electrolytes for Li-ion and other ion batteries. Herein, we review and summarize the recent advances of hydrides as negative electrodes for Ni- M H and A -ion batteries ( A = Li, Na), and as electrolyte for all solid-state batteries (ASSB). Metallic hydrides such as intergrowth compounds are highlighted as the best compromise up to now for Ni- M H. Regarding anodes of Li-ion batteries, MgH 2 , especially its combination with TiH 2 , provides very promising results. Complex hydrides such as Li-borohydride and related closo-borates and monovalent carborate boron clusters appear to be very attractive as solid electrolytes for Li-based ASSB, whereas closo-hydroborate sodium salts and closo-carboborates are investigated for Na- and Mg-ASSB. Finally, further research directions are foreseen for hydrides in electrochemical applications.

Separation of lanthanum and neodymium in a hollow fiber supported liquid membrane: CFD modelling and experimental validation

Nickel metal hydride batteries find extensive use in many electronic devices. They contain a small amount of rare earth elements, such as, lanthanum and neodymium, which can be recovered from waste batteries, and reused. Hollow fiber supported liquid membranes (HFSLM) have been used for separation of different metal ions. In this work, a CFD model has been developed for a HFSLM to study the separation of lanthanum ion (La+3) and neodymium ion (Nd+3) from an aqueous solution. The model considers the effect of pH on distribution coefficient DM, which is a function of hydrogen ion (H+) concentration, and has a significant effect on extraction efficiency. The model was validated with the experimental data. An empirical model was fitted with the simulation data, and the parameters were optimized for the effective separation of La+3 and Nd+3. The maximum extraction of Nd+3 was predicted to be 44.97%, whereas extraction of La+3 was estimated to be 3.39%, at the optimized conditions of flow rate: 118.96 ml/min, feed pH: 3.41, and [PC88A]: 41.63 mol/m3, in once-through mode. The proposed CFD model could be helpful in design as well as, scale-up of HFSLM for separation of metal ions, by changing the design and process parameters.

On-line WSN SoC estimation using Gaussian Process Regression: An Adaptive Machine Learning Approach

Wireless sensor networks (WSN) are low-resource devices that run on small batteries. The availability of battery energy, device drive cycles, and environmental conditions all have an impact on node lifetime. The state of charge (SoC) is an important factor in determining the amount of energy available in the batteries. Accurate SoC estimation is critical for device lifetime prediction and safe device operation. We present a novel approach for adaptive SoC estimation based on Gaussian Process Regression in this paper (GPR). The training data was obtained in a climate-controlled laboratory setting by using IEEE 802.15.4-based drive loads at various temperatures for three different batteries such as Lithium-Ion, Nickel-metal hydride, and Lithium-Polymer. To estimate the SoC, battery parameters such as voltage, capacity, and temperature were directly mapped to the corresponding models. For each battery parameter, the GPR model with hyper tuned Radial Bias Filter (RBF) was trained at temperatures ranging from 5 °C to 45 °C. For model accuracy, the proposed scheme was compared to polynomial regression and support vector machines (SVM). In this regard, the proposed model provided Mean Absolute Error (MAE) values of 2.53 percent, 2.54 percent, and 2 percent, respectively, and Root Mean Square Error (RMSE) values of 0.295, 0.292, and 0.35 for Nickel-metal hydride, Lithium-Polymer, and Lithium-Ion batteries at 25 °C. Our proposed lightweight GPR scheme is, to the best of our knowledge, the only active implementation on embedded platforms for SoC estimation of WSN. Finally, the model was rigorously tested on ARM Cortex M4-based microcontrollers to report real-time online SoC estimation on WSN nodes.

Model-based design validation and optimization of drive systems in electric, hybrid, plug-in hybrid and fuel cell vehicles

We are currently immersed in the fourth industrial revolution, which involves, among others, technology to prevent climate change, transformation of the transport sector, digitization, and artificial intelligence. This paper contributes to technological development accelerating the design of ecological vehicles and their introduction in smart cities.This paper describes an adaptive, flexible, expandable, simple, and high-accuracy methodology capable of maximizing vehicle range with the finest computational effort, thanks to a genetic algorithm. Further, it produces predictive information to minimize cost, volume, and weight of the drivetrain in the vehicle structure while meeting the desires of the designer.Range is calculated using a standard or customised drive cycle. Calculation of the CO2 produced in the electricity production process is also provided. The reliability of the system has been verified with commercially available vehicles, taking into account their technical specifications such as electric motor type (e.g. induction, permanent magnet, or hybrid electric motors), the technology of the energy storage system (e.g. nickel-metal hydride or lithium-ion batteries or fuel cell), configuration (e.g. pure electric vehicle, series/parallel/series-parallel (plug-in) hybrid electric vehicle, or fuel cell vehicle) and their category (light quadricycles [L6e], heavy quadricycles [L7e], passenger cars [M1], vans [N1], or low-speed vehicles). The results obtained demonstrate that the model is capable of extraordinary precision.

Metal leaching from Lithium-ion and Nickel-metal hydride batteries and photovoltaic modules in simulated landfill leachates and municipal solid waste materials

• The end-of-life impacts of batteries and photovoltaics in landfills was examined. • TCLP guided tests indicated that some should be classified as hazardous waste. • Additional work is needed to develop appropriate EoL procedures for MSW with e-waste. Photovoltaic (PV) modules and batteries can either be recycled or disposed of in landfills at end-of-life (EoL). This work focuses on disposal since the benefit of recycling PV modules and batteries is well established. This study characterizes the potential toxicity due to metals leaching from selected PV modules and batteries through both the Toxicity Characteristic Leaching Procedure (TCLP) and in-house batch leaching protocols to probe the impact on metallic ion mobility as a function of the different types of e-waste entering the waste stream, the magnitude of device damage when placed into the waste stream, and the simulated municipal solid waste (SMSW) composition. Our results showed that one PV module and three battery types in this study should be classified as hazardous waste within the U.S. However, for some of the other e-wastes, metals of concern including Cr, Cu, Hg, Ni, Pb, and Zn leached during the batch tests but not in the TCLP regulatory method. For most of the waste types, the amounts of metals that leached in the TCLP test and batch tests were much lower than the total extractable amounts, demonstrating the potential for additional unaccounted for amounts of metals to leach. These results demonstrate that the TCLP regulatory method might fail at predicting potential leaching and at capturing the complexity of e-waste leaching in landfill conditions. It confirms that additional work is needed urgently to develop appropriate EoL procedures for MSW with PV and battery e-waste.

Electrochemical hydrogen evolution reaction over Co/P doped carbon derived from triethyl phosphite-deposited 2D nanosheets of Co/Al layered double hydroxides

Hydrogen is widely considered an emissions-free alternative energy carrier for sustainable energy devices, such as fuel cells and nickel-metal hydride batteries. Recently, electrochemical hydrogen evolution reaction (HER) from water splitting has been attracted as an eco-friendly process for producing hydrogen. Herein, we report a Co/P-doped carbon material (Co/P/C) derived from cobalt-aluminum layered double hydroxide nanosheets (LDHs) for HER. The Co/P/C was synthesized using triethyl phosphite as phosphate and carbon sources by a one-step chemical vapor deposition (CVD) process. The regular arrangement of Co and Al atoms in the precursor LDHs allowed Co/P species to be highly dispersed under optimized CVD conditions. The carbon nanotube formed by the CVD process improved the catalytic activity of Co/P/C. The optimized Co/P/C exhibits a low overpotential of 240 mV at −10 mA cm −2 for HER, comparable to the commercial Pt/C catalyst. This work provides a new direction for developing transition-metal and hetero-atom co-doped carbon materials with high catalytic activity for HER. • Co/P-doped carbon materials are prepared by using layered double hydroxide. • The metal aggregation was prevented by the unique of the layered double hydroxide. • The deposition process using triethyl phosphite can introduce desire Co/P species. • The synthesized Co/P/C shows excellent activity for HER in an acidic media.

SYNTHESIS AND ELECTROCHEMICAL HYDROGENATION OF Tb2Co17-х-ySbxLiy AND Tb2Co17-х-yAlxMgy PHASES

Metal hydride batteries have a high sorption ability to the reverse hydrogen absorption, moderate pressure and temperature of the processes of hydrogen sorption-desorption and stability to cycling. We synthesized doped derivatives of binary intermetallic compound consisting terbium with cobalt to establish electrochemical properties when using them as anode materials in prototypes of nickel metal hydride batteries. The samples were made of high purity metals in an electric arc furnace in an argon atmosphere. Phase analysis was performed using X-ray diffraction data obtained on the DRON-2.0M powder diffractometer (Fe Kα-radiation). Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray fluorescence spectroscopy (XRF) were used to determine the quantitative and qualitative composition of the alloys. Electrochemical hydrogenation was performed in Swagelok cell two-electrode prototypes of chemical sources of electric current on a two-channel MTech G410-2 galvanostat in galvanostatic mode at a current density of 1.0 mA/cm2. The elemental composition of the Tb2Co16.5Sb0.2Li0.3 and Tb2Co16Al0.5Mg0.5 samples before and after hydrogenation was determined by the XRF method, a slight decrease in the content of terbium on the surface was found. Phase analysis of diffractograms of both samples before and after electrochemical hydrogenation showed that they contain hexagonal phases with a stoichiometry of 2:17. Only a phase with a structure of the Th2Ni17 type was found in the Tb2Co16.5Sb0.2Li0.3 alloy. In the Tb2Co16Al0.5Mg0.5 sample, in addition to the main phase with Th2Ni17 structure, the existence of another hexagonal phase with a similar crystal structure (TbCo5-x-yMgxAly) was detected. The results of X-ray diffraction of the Tb2Co16Al0.5Mg0.5 sample are fully consistent with the results of EDX analysis. The Tb2Co16.5Sb0.2Li0.3-based electrode undergoes significant amorphization due to the active hydrogenation/dehydrogenation process, but the hydrogen absorption properties remain acceptable. The cell parameters after hydrogenation increase, which indicates the inclusion of hydrogen atoms into the structure. The amount of deintercalated Hydrogen under experimental conditions is approximately 0.40 H/f.u. The Coulomb efficiency on the 10th cycle is equal to 81.3%, and on the 20th cycle is 90.2%. The Ni-MH battery prototype with the Tb2Co16Al0.5Mg0.5-based electrode demonstrates good reproducibility and Coulomb efficiency. The amount of deintercalated Hydrogen under experimental conditions is approximately 0.44 H/f.u. The Coulomb efficiency on the 10th cycle is 95.5%, and on the 20th is equal to 93.4%. Due to the amorphization processes as the number of cycles increases, the charging plateau voltage increases and a small decrease in the capacitive parameter τ is observed similarly to the Li,Sb-containing electrode. As electrode materials both alloys showed corrosion resistance in the electrolyte solution. Keywords: terbium; cobalt; solid solutions; crystal structure; electrochemical hydrogenation; anode materials.

Tailoring of a highly stable Mn1−x−y(CexLay)O2−δ pseudocapacitor thin-film and rare earth oxide nanospheres through selective purification of rare earth oxides derived from Ni–MH batteries

High-yield fabrication of two value-added functional nanostructures including a defect-rich Mn1−x−y(CexLay)O2−δ film and rare earth oxide (REO) nanospheres via selective purification of REO isolated from end-of-life nickel–metal hydride batteries.

Nickel-Cobalt Layered Double Hydroxide Cathode Materials with Excellent Cycle Stability for Nickel-Metal Hydride Batteries

Nickel-Cobalt Layered Double Hydroxide Cathode Materials with Excellent Cycle Stability for Nickel-Metal Hydride Batteries