Batteries high-temperature performers

To overcome the difficulties met with LiPFe, attempts have been made to replace it by another salt without any fluorine in the chemical formula. Lithium bis(oxalato) borate (LiBOB) was initially studied as an alternative salt to improve the high-temperature performance of Li-ion batteries [64], but it also significantly stabilizes SEI during extended cycling [65]. Jiang and Dahn systematically investigated the safety feature of LiBOB with various electrode materials by means of accelerating rate calorimetry (ARC)... 

It has been found that a lithium secondary battery with a noticeably improved high-temperature performance and lifespan characteristics can be fabricated by adding a polyalkyleneglycol diglycidylether to the electrolyte of the battery (105). 

The high-temperature performance of nickel-metal hydride batteries is directly related to the behavior of the nickel hydroxide electrode materials, which determines the cell capacity. Due to oxygen evolution on the positive electrode at a temperature higher than 50°C, the charge efficiency of positive electrodes is significantly diminished when the rmdesirable oxygen evolution reaction occurs. 

An alternative approach to improve the high-temperature performance of nickel-metal hydride batteries has been proposed by introducing a NaOH electrolyte containing NaBC>2 additives. The paste nickel electrodes were prepared as follows (114) ... 

In order to improve the high-temperature performance of the nickel hydroxide electrodes in nickel-metal hydride batteries, sodium tungstate (Na2W04) was used as an electrolyte additive (115). It was added into two types of binary electrolytes, i.e., KOH-LiOH and NaOH-LiOH. 

Sodium tungstate, (Na2W04, was tested as an electrolyte additive to enhance the high-temperature performance of a nickel-metal hydride battery (116). The effects of Na2W04 on nickel hydroxide electrodes have been investigated by CV, EIS, and a charge/discharge test. 

Barium improves the performance of lead ahoy grids of acid batteries (see Batteries) (34). In the form of thin films, barium has been found to be a good high temperature lubricant on the rotors of anodes operating at 3500 rpm ia vacuum x-ray tubes (35). 

The poor efficiencies of coal-fired power plants in 1896 (2.6 percent on average compared with over forty percent one hundred years later) prompted W. W. Jacques to invent the high temperature (500°C to 600°C [900°F to 1100°F]) fuel cell, and then build a lOO-cell battery to produce electricity from coal combustion. The battery operated intermittently for six months, but with diminishing performance, the carbon dioxide generated and present in the air reacted with and consumed its molten potassium hydroxide electrolyte. In 1910, E. Bauer substituted molten salts (e.g., carbonates, silicates, and borates) and used molten silver as the oxygen electrode. Numerous molten salt batteiy systems have since evolved to handle peak loads in electric power plants, and for electric vehicle propulsion. Of particular note is the sodium and nickel chloride couple in a molten chloroalumi-nate salt electrolyte for electric vehicle propulsion. One special feature is the use of a semi-permeable aluminum oxide ceramic separator to prevent lithium ions from diffusing to the sodium electrode, but still allow the opposing flow of sodium ions. 

Compared with the Leclanche batteries, alkaline manganese dioxide batteries offer better performance at high discharge currents and lower temperatures and a better shelf life. They are more expensive than Leclanche batteries, but their cost per unit of energy is competitive and resources of raw materials are sufficient for mass production of these batteries. 

However, certain restrictions on battery performance arise from these state-of-the-art electrolytes, for which these two indispensable components are mainly responsible (1) a low-temperature limit (—20 °C) set by EC due to the high melting point and the high liquidus temperature it confers upon the solvent mixture, and (2) a high-temperature limit (50 °C) set by LiPEe due to its reactivity with solvents. As a result, the commercialized lithium ion batteries can... 

Vented NiCd. The vented NiCd battery is one of the best-known power sources in the commercial and military fields, particularly for aircraft and communication applications. It has excellent high rate and low temperature performance capabilities. It also has a long useful life capability and is both physically and electrochemically rugged. 

The most important use of barium is as a scavenger in electronic tubes. The metal, often in powder form or as an alloy with aluminum, is employed to remove the last traces of gases from vacuum and television picture tubes. Alloys of barium have numerous applications. It is incorporated to lead alloy grids of acid batteries for better performance and added to molten steel and metals in deoxidizing alloys to lower the oxygen content. Thin films of barium are used as lubricant suitable at high temperatures on the rotors of anodes in vacuum X-ray tubes and on alloys used for spark plugs. A few radioactive isotopes of this element find applications in nuclear reactions and spectrometry. 

Nickel-cadmium batteries with thin sintered plates are used for on-board power supplies in aircraft, helicopters, tanks and military vehicles where their excellent low temperature, high rate performance is an important attribute. Modern 40 Ah cells designed for airborne use can deliver 20 kW of instantaneous power at 25°C and over 10 kW at —30DC. Again, the high cost of this system compared with that of lead-acid batteries has restricted its use. 

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