Nickel negative electrode reaction

Electrochemical Processes The charged positive electrodes of these batteries contain NiOOH, an oxide hydroxide of trivalent nickel, and the negative electrodes contain metallic cadmium or iron (M). As a rule, KOH solution serves as the electrolyte. The main current-producing reactions on the electrodes and in the cell in general can be written as... 

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... 

Nickel-cadmium batteries use a hydrate nickel oxide as positive electrode, a metallic cadmium as negative electrode and an aqueous solution of potassium hydroxide as electrolyte [17]. The production of electrons at the negative plate during discharge occurs via the following semi-reaction ... 

The negative electrode, in the charged state, is hydrogen in the form of metal hydride, the positive is nickel oxyhydroxide and the electrolyte is a KOH solution. The overall reaction is ... 

The main current-producing reactions on the negative electrodes of alkaline nickel storage batteries can be written as... 

As described in the relevant report, the tert-aUcylbenzene compound decomposes by oxidation at a potential of +4.6 to +5.0 V (relative value to that of lithium), and cobalt or nickel in the positive electrode rapidly dissolves and deposits on the negative electrode to inhibit a reaction of a carbonate in the non-aqueous electrolytic solution with a lithium metal deposited on the negative electrode. Further, in the invention, the internal short circuit may be formed in the battery by the deposition of cobalt and nickel, whereby the overcharge inhibitive effect can be attained and the safety of battery can be assured [133]. 

As described above, LiNi02 is an attractive material for lithium-ion batteries. However, it is difficult to operate high-volume lithium-ion batteries consisting of LiNiOj and (natural) graphite (or other negative electrode materials) safely for thousands of cycles. The difficulty is associated with the formation of nickel dioxide, so that it is hopeless to cope with this problem in a usual manner. However, it may be possible using a characteristic feature of the solid-state redox reaction of... 

The electrodes are referred to as anode and cathode in battery assembly. Anode is the positive electrode that is normally oxidized, ie, loses electrons in a chemical reaction within the cell. An anode should be an efficient reducing agent with good conductivity. Metallic materials such as zinc, nickel, and lithium are often used as anode materials. Cathode is the negative electrode, normally a metal oxide or sulfide, that is reduced or gains electrons. The main properties of a cathode material are that it should be an efficient oxidizing agent and should be stable when it comes into contact with electrolytes. 

ZEBRA battery is actually a Z E B R A (Zeolite Battery Research Africa) battery, that is, sodium-nickel chloride cell. This battery consists of a liquid Na negative electrode and NiCU separated by S-alumina solid electrolyte with Na" conduction. Total cell reaction is as follows ... 

The situation with respect to secondary reactions is shown in Fig. 1.34. It is similar to that in the nickel/cadmium battery shown in Fig. 1.32 as far as the positive electrode is concerned. Different is the situation at the negative electrode. The electrode potential is nearly the same, since the equilibrium potential of the hydrogen electrode is only about 20 mV below that of the cadmium electrode. But now hydrogen is used as active material instead of cadmium, and hydrogen evolution as well as hydrogen oxidation are fast reactions, since both are catalyzed by the platinum surface of the negative electrode. 

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