Nickel-metal hybrid batteries

New battery systems could give better performance but they have not been forthcoming. Performance is limited by the lead-acid battery packs which are generally the most affordable option. More unfamiliar batteries like nickel metal hybride (NiMH) packs have also appeared. 

Rechargeable lithium ion batteries are of great importance at the present time due to their superiority in terms of volumetric and gravimetric energy density and cycle life, in comparison with their traditional counterparts including value regulated lead acid (VRLA), nickel cadmium (Ni-Cd), and nickel metal hybrid... 

The Peugeot Quark ATV uses an air-cooled fuel cell with a 40 cell nickel metal hybrid battery. The 9 liter hydrogen tank can be pressurized to 10,150 psi for a range of up to 80 miles. The tank is designed to be exchanged for a full one when empty. Each 17 inch wheel has its own electric motor that can produce 74 pound-feet of torque. The motors also supply regenerative braking. 

There is considerable interest in the development of nickel-metal hybrid (Ni/MH) batteries for electric and hybrid vehicles. These batteries operate in concentrated KOH electrolyte. The electrode reactions are ... 

Examples of EV NiMH battery packs for the General Motors EVl and S-10 pickup truck are shown in Fig. 30.1. In addition, nickel metal-hybride batteries are being used in industrial applications, replacing nickel-cadmium batteries and are being considered as a replacement for lead-acid batteries in SLI applications. 

Besides being environmentally friendher than Nicad batteries, nickel-metal hydride batteries have a higher energy content per unit mass. This is called the battery s energy density with units expressed in watt-hour/kg. These batteries are commonly used in hybrid electric cars and buses. 

High-power lithium-ion batteries are promising alternatives to the nickel metal hydride batteries which are currently used for energy storage in hybrid electric vehicles (HEVs). Currently, Li(Ni,Co)02-based materials are the most widely studied cathode materials for the high-power lithium-ion batteries [1-4]. Although Li(Ni,Co)02-based materials meet the initial power requirement for the HEY application, however, it has been reported that they... 

Toyota s Prius uses the heavy, range-limited nickel-metal hydride battery, basically because it is safe. The Prius recaptures the braking energy (instead of wasting it in friction) and runs on electric power in stop-and-start traffic, but its all-electric mode of operation is limited. Toyota s Prius is also available in a version that has been converted to hydrogen by Quantum Fuel Systems. Toyota is planning to have a hybrid version of all its 2010 models. 

The early electric cars used the old lead-acid batteries. Today s hybrids are provided with more robust nickel-metal units. The EVs of the future are likely to be provided with lithium-iron batteries, found in today s laptops and cell phones. Much work remains to be done in this area to increase safety and life span (to 100,000 mi of driving), while reducing their cost. Nissan and Mitsubishi are both making major investments in building lithium-ion battery mass production plants. 

Lanthanum is also used in nickel-metal hydride (NiMH) batteries found in some hybrid cars. 

Nickel-metal-hydride batteries of both prismatic and cylindrical cell designs are now available for automotive use. In 2003, the fleet of hybrid vehicles with Ni-MH batteries is more than 100,000 world-wide, most of these are in Japan. This can be considered as a significant and reliable fleet test that demonstrates the maturity of this battery system for automotive use [70]. 

Nickel-metal hydride (Ni-MH) secondary batteries are a typical example of H° applications and have been widely used as rechargeable batteries for CD cameras, cordless tools, and hybrid cars. The Ni-MH battery is based on the internal reversibility between the electrochemical charge and discharge of protium in aqueous KOH solutions ... 

In 1997, Toyota Motor Company launched electric hybrid vehicles into the world market, followed by Nissan and Honda a few years later. They were very popular because of the good fuel economy and the increasing interest in global environmental issue. Therefore, all of the car manufacturers worldwide accelerated their research and development for hybrid electric vehicle (HEV) technology. Although the batteries used for HEV by Toyota and Honda are nickel-metal hydride (Ni-MH) batteries and they are major batteries in the field at present, the pressure for development is put on not Ni-MH but lithium because of the superior characteristics in power, weight, heat generation, and so on to Ni-MH. 

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