Nickel sealed-type

Focusing on the concept of the completely sealed system, the Sanyo Electric Co. developed sealed-type nickel-cadmium batteries in 1961. This type of battery enjoys a wide application range that is still expanding a large variety of nickel-cadmium batteries has been developed to meet user needs ranging from low-current uses like emergency power sources and semiconductor memories to high-power applications such as cordless drills. 

For many years, sintered-nickel electrodes have been used as the positive electrodes for sealed-type nickel-cadmium batteries. With an increase in the demand for high energy density, this type of elec-... 

Engineering Handbook of Sealed Type Nickel-Cadmium Batteries, Sanyo Electric Co., Ltd., Osaka, 1988. 

Batteries, Dry. Are sealed, non-vented batteries of the type used in flashlights or for the operation of small apparatus. They contain zinc salts and other solids, or may be of the nickel cadmium type or other combinations of metals. Such batteries must be packed in inner packagings in such a manner as to effectively prevent short circuits and to prevent movement which could lead to short circuits. lATA App. A... 

Cadnica sealed type Nickel-Cadmium batteries engineering handbook, Sanyo Electric Company, Osaka... 

Then, A. B. Lange and others found how a cadmium electrode consumes the oxygen from a positive electrode during overcharging in 1938. Then, G. Neumann and others established the present sealing principle and basic structure of a sealed-type nickel-cadmium secondary battery in 1948. Then, the sealed-type nickel-cadmium secondary battery has come to rapidly spread mainly in the consumer electronic equipment market. 

On the other hand, Sanyo Electric Co., Ltd. started mass production of a consumer sealed type nickel-cadmium secondary battery. Then, other companies produced a consumer sealed-type nickel-cadmium secondary battery commercially one after another. Then, the batteries have been used as the main power supply of portable electronic devices such as cordless power tools and toys, video cameras, and notebook PCs in 1980s, and the production amount has enlarged drastically. 

Both sealed and open nickel-eadmium batteries are based on similar chemical reactions. The sealed type is designed to be maintenance free and under normal conditions will not release gas, whereas an open battery has been designed to release gases when... 

Tlie cover assembly usually contains a safety v ent. Tlie most common type consists of a steel or nickel diaphragm built into the cov er and a bent point cut from the cov er. At a certain internal cell pressure, the diaphragm niov es to the bent point and is pierced. Some cylindrical sealed cells use one or more temiinal feed-throughs employing glass-to-metal or ceramic-to-metal techniques. 

Fig. 7. Section of disk-type cell where 1, is the cell cup 2, is the bottom insert 3, is the separator 4, is the negatwe electrode 5, is the positive electrode 6, is the nickel whe gauze 7, is the sealing washer 8, is the contact spring and 9, is the cell cover.

CeU terminal connections are usuaUy brought out by two-threaded terminals that protmde through the ceU jar cover. They are usuaUy steel, brass, or copper with a hoUow coastmctioa. The plate leads are soldered ia place ia the ceater hoUow portioa of the terminal to effect an electrical contact and ceU seal. The terminal itself is potted iato the jar cover usiag epoxy-type pottiag compouads. NormaUy, terminal hardware is sUver-plated. However, for corrosioa resistance nickel-plating has been used. 

The bipolar plates are made from either Type 310 or Type 316 stainless steel, which is coated on the fuel side with nickel and aluminized in the seal area around the edge of the plates. Both internally and externally manifolded stacks have been developed. 

Fig. 1 5 . Beaker-type cell for oxidations with the nickel hydroxide electrode. A Inlet and outlet for circulation (pumping) of the electrolyte B Teflon-stopper (d = 80 nun) C Silicon seal D Stainless steel cathode E Glass rods F Nickel net anode G Magnetic stirrer...

Cell construction is mainly confined to two types, using either pocket plate electrodes (vented cells) or sintered , bonded or fibre plate electrodes (vented and sealed cells). In the former, the active materials are retained within pockets of finely perforated nickel-plated sheet steel which are interlocked to form a plate. Positive and negative plates are then interleaved with insulating spacers placed between them. In sintered plate electrodes, a porous sintered nickel mass is formed and the active materials are distributed within the pores. In sintered plate vented cells, cellulose or other membrane materials are used in combination with a woven nylon separator. In sealed or recombining cells, special nylon separators are used which permit rapid oxygen diffusion through the electrolyte layer. 

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