Separators for Batteries

Separators for batteries can be divided into different types, depending on their physical and chemical characteristics. They can be molded, woven, non-woven, microporous, bonded, papers, or laminates. In recent years, there has been a trend to develop solid and gelled electrolytes that combine the electrolyte and separator into a single component. 

Y. Sudou, H. Suzuki, S. Nagami, K. Ikuta, T. Yamamoto, S. Okijima, S. Suzuki, and H. Ueshima, Separator for battery and lithium ion battery using the same, US Patent 7183 020, assigned to Mitsui Chemicals, Inc. (Tokyo, JP) Denso Corporation (Aichi, JP), February 27, 2007. 

Separators for batteries can be divided into different types, depending on their physical and chemical characteristics. They can be molded, woven, nonwoven,... 

The remaining 40% or more are split among the recently introduced lithium-ion batteries as well as a multitude of primary systems in the portable battery sector. This distribution of battery production is not geographically uniform whereas in Europe and the USA automotive and industrial batteries are in the lead, in the Asia-Pacific area consumer batteries are more strongly represented. In this section separators for mainly those rechargeable batteries which have aqueous electrolyte will be discussed individually, whereas separators for batteries with nonaqueous... 

In batteries, separators are used to avoid short circuit between negative and positive electrodes. They are therefore generally regarded to be conductors not of electrons but of ions. Some separators for batteries and their properties are shown in Table 12.1 [1]. 

EGSG Idaho s Idaho National Engineering Laboratory reviewed Licensee Event Reports (LERs), both qualitatively and quantitatively, to extract reliability information in support of the USNRC s effort to gather and analyze component failure data for U.S. commercial nuclear power plants. LERs describing failures or command faults (failure due to lack of needed input) for selected components have been analyzed in this program. Separate reports have been issued for batteries and battery chargers, control rods and drive mechanisms, diesel generators, ISC, Inverters, primary containment penetrations, protective relays and circuit breakers, pumps, and valves. 

Separate reheat batteries may be placed in branch ducts where one plant supplies both a main area calling for cooling and an auxiliary room without heat load. Correct rh in the auxiliary rooms results (only) if it is correctly controlled in the main room and they require the same dry bulb temperature. While wasteful of energy, it simplifies the plant design and may be found to use fewer resources. 

The tubular-plate design for the positive electrodes, shown in Fig. 7, is common mainly in European countries for batteries with larger capacities. In this plate design, the conducting elements are separated... 

A comprehensive modern survey of separators for electrochemical power sources exists only in incomplete parts [1-3], and textbooks on batteries treat this important element only as a side aspect [4-11]. This section is an attempt to describe, besides some fundamental aspects, the development history of the battery separator,... 

There are no indications, or only vague ones, of the size of the various battery separator markets in the literature 131. A rough estimate can be deduced from the sales figures for battery systems by a rule of thumb the sales value of separators is roughly 2-5% of the sales for the battery producers. Even the data for battery markets are not uniformly gathered, however, and contain considerable uncertainties. 

The total sales value for battery systems worldwide in 1997 may amount to US 25.5 billion and the sales value for battery separators correspondingly to US 600 million Table 1 gives an estimate of the work battery market, split according to the different battery systems. 

In the second half of the 1960s, at the same time but independently, three basically different plastic separators were developed. One was the polyethylene separator [16] already referred to in starter batteries, used only rarely in stationary batteries, but successful in traction batteries. The others were the microporous phenolic resin separator (DARAK) [18] and a microporous PVC separator [19], both of which became accepted as the standard separation for stationary batteries. They distinguish themselves by high porosity (about 70 percent) and thus very low electrical resistance and very low acid displacement, both important criteria for stationary batteries. 

Table 11. Separators for lead-acid traction batteries...

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