Nickel metal hydroxide secondary

Nickel/cadmium batteries (line 8 in Table 1.1) have been in technical use nearly as long as lead-acid batteries. They belong to a whole family of secondary batteries that are based on aqueous, but alkaline electrolyte, usually diluted potassium hydroxide. Nickel/cadmium, nickel/hydrogen, and nickel/metal hydride batteries are the most important members of this group. A further common feature of these battery systems is that they employ the nickel-hydroxide electrode as the positive one. Some of their basic features will be described in the following. 

Layered nickel hydroxide can be used as an electrode for alkaline secondary cells. To improve its properties, modification has been carried out by incorporation of other metal elements to form Ni/M LDHs, including Co [221], Zn [222], Al [223], Cr or Mn [224] and Fe [225]. For example, Chen et al. reported the electrochemical performance of Al-substituted layered a-... 

Edison cell — A nickel-iron (Ni-Fe) secondary (rechargeable) cell independently developed by Edison in USA and W. Jiinger in Sweden in 1900. The cell (-> battery) is based on the use of nickel oxyhydroxide (NiOOH) at the positive electrode and metallic iron for the negative electrode, and a potassium hydroxide (KOH) solution containing lithium hydroxide (LiOH) is the electrolyte. The Ni-Fe cell is represented as ( Fe/KOH/NiOOH. The charge-discharge reactions for the Edison (Ni-Fe) cell are as follows ... 

Ni-Cd cells — The nickel-cadmium cell is a secondary - battery that has a nominal cell potential of 1.20-1.25 V. The negative electrode comprises nickel hydroxide-nickel oxyhydroxide, the positive electrode is cadmium, and the electrolyte solution is based on aqueous potassium hydroxide (KOH, 32% in water). At the anode, the discharge reaction is the oxidation of cadmium metal to cadmium hydroxide with the release of two electrons [i] ... 

Ni-MH cell — A -> secondary battery (-> accumulator) containing a nickel hydroxide positive electrode, a metal hydride negative electrode, and a strongly alkaline aqueous electrolyte solution. The electrode reactions are... 

The two principle products from the addition of sulphur to Et2P(S)H are the phosphin-odithoic acid, Et2PSSH, and the trisulphane, 174 (R = Et, Z = Z = S, = 3)(Scheme 48), which can be separated wthout too much difficulty. In many cases, the phosphinodithioic acids may be isolated as the salt of a heavy metal such as nickel, but a better synthesis procedure consists in the addition of the sulphur to the secondary phosphine sulphide in aqueous alkali (ammonia solution provides better yields than sodium hydroxide), when the polysulphane—the principle by-product—is broken down under the influence of the alkali metal sulphide. A phosphinodiselenoic acid may be obtained in essentially the same... 

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