La-mg-ni type negative electrode hydrogen storage material for secondary rechargeable nickel-hydrogen battery and preparation method thereof

Abstract

The invention discloses a La-Mg-Ni type negative electrode hydrogen storage material for a secondary rechargeable nickel-hydrogen battery and a preparation method thereof. The chemical formula of the La-Mg-Ni type negative electrode hydrogen storage material is La 1‑x‑ y Re x Mg y (Ni 1‑a‑b Al a m b ) z , wherein, Re is at least one of Ce, Pr, Nd, Sm, Y, M is at least one of Ti, Cr, Mo, Nb, Ga, V, Si, Zn, Sn; 0≤x≤0.10 , 0.3≤y≤0.5, 0

Description

technical field [0001] The invention belongs to the field of battery materials, and relates to a La-Mg-Ni type negative electrode hydrogen storage material for a secondary rechargeable nickel-hydrogen battery. Background technique [0002] Since the metal hydride-nickel battery was put into the market in the 1990s, due to its high capacity, long life, no memory effect, and no environmental pollution, it has been widely welcomed, and its market share is increasing. The types of batteries are also increasing. From AA and AAA ordinary batteries to other types, the products are widely used in electric tools, household appliances, computers, aerospace, communications and mopeds, etc., and the development is very rapid. With the increase in the application fields of metal hydride-nickel batteries, the requirements for battery performance are also getting higher and higher. Especially in recent years, people have gradually realized that the storage performance and self-discharge c...

AI Technical Summary

Problems solved by technology

[0003] The self-discharge of the battery is mainly due to the combination of the oxygen precipitation of the positive electrode and the hydrogen of the negative electrode when the battery is not working, on the other hand, the negative electrode contains Co and Mn, or other substances soluble in alkaline electrolyte. These elements will be deposited on the separator after being dissolved in the electrolyte, thereby accelerating the reduction of the positive electrode. For this reason, people have done a lot of work, such as coating the positive electrode powder with cobalt, improving the separator and the electrolyte, and in the positive and negative Adding some stabilizing additives to the electrode, these works have indeed improved the self-discharge characteristics of Ni-MH batteries, but still have not fundamentally solved the problem.

[0004] In addition, as shown in Tables 1 and 2 below, AB x (LaNi 2 , LaNi 3 , La 2 Ni 7 , La 5 Ni 19 , LaNi 5 ) composed of rare earth intermetallic compounds, with the increase of A-side rare earth content, the hydrogen absorption capacity of the compound increases, and the theoretical electrochemical capacity is also high, but the equilibrium hydrogen pressure and hydrogen absorption and desorption temperature also increase (see Table 1), so that It is difficult to get practical application

Images