TW574375B - Hydrogen absorbing alloy - Google Patents

Abstract

A hydrogen absorbing alloy which is represented by the formula ABv; wherein A is Lm which comprises 5 to 25% by weight of Ce, at most 20% by weight of Pr and Nd and La is the other; Bv consists of the metal of Ni, Co, Mn and Al, v is number of mole, 4.3 <= v <= 5.2; Bv represents a formula NiwCoxMnyAlz, v=w+x+y+z, wherein 0.5 <= x <= 0.85, 0.2 <= y <= 0.5, 0.1 <= z <= 0.4 and w is the other.

Description

574375 V. Description of the invention (i) The present invention relates to hydrogen absorbing alloys, especially hydrogen absorbing alloys with high hydrogen absorption capacity, low period and low manufacturing cost. Lean hydrogen absorbing alloys can be used for communication, information computers, and consumer goods. The so-called 3 sub-products, such as the negative electrode materials of I-type nickel-metal hydride batteries, can also be used as power tools, assisted self-light vehicles, electric vehicles, etc. The anode material of rechargeable nickel-metal hydride battery is widely used. The composition elements, the ratio of the elements, and the manufacturing method of the hydrogen-absorbing alloy all affect the hydrogen absorption amount, lifetime (usage number), and manufacturing cost of the hydrogen-absorbing alloy; the hydrogen absorption amount, lifetime, and Manufacturing costs have commercial value. National Patent Bulletin No. 363288 r Hydrogen Retention Alloys for Rechargeable Electrochemical Cells and Their Manufacturing Methods ", the disclosed hydrogen retention alloys include expensive titanium and junction elements, and their manufacturing costs are relatively high. . In order to obtain a nitrogen-absorbing alloy with high hydrogen absorption, long life, easy manufacturing and low cost, the present inventors finally completed the present invention after repeated studies and tests by the inventors. The main object of the present invention is to provide a hydrogen absorbing alloy with a high hydrogen absorption amount and a long life. Another object of the present invention is to provide a gold-absorbing alloy which is easy to manufacture and at a low cost. For other purposes, effects and embodiments of the present invention, please refer to the drawings, which are described in detail as follows: The drawings are briefly explained: FIG. 1 is a flowchart of a method for manufacturing the gold-absorbing alloy of the present invention. FIG. 2 is a heating temperature curve diagram of the gold-absorbing alloy dazzling chain treatment of the present invention. FIG. 3 is a heating temperature curve diagram of the homogenization treatment of the gold-absorbing alloy according to the present invention.

574375 V. Description of the invention (2) Fig. 4 is a graph showing the relationship between the hydrogen absorption and desorption amount and pressure of the A B5 hydrogen absorbing alloy of the present invention. Figure 5 is a diagram of the main system types for the development of general rare earth-based hydrogen storage alloys. FIG. 6 is a composition diagram of the hydrogen storage alloy in the Patent No. 363288. FIG. 7 is a composition chart of a gold-absorbing alloy according to the present invention. -The general formula of the composition of the hydrogen-absorbing alloy of the present invention is ABv, where AgLm (rich lanthanum) metal includes Ce (钸) with a wt% (weight percentage) of 5-25 wt%, Pr (wrong) and Nd within 20 wt% (Convergence), the rest is La (lanthanum); Bv includes metals such as Ni (nickel), Co (cobalt), Mn (manganese), and A1 (aluminum), ν is the mole number of B, 4 · 3 $ ν $ 5 · 2; The composition of Βν is _ General formula is NiwCoxMnyAlz, v = w + x + y + z; The values of w, χ, y, and z are: 0.5 $ χ $ 〇 · 85, 0 · 2 $ γ $ 0.5, 〇 · ΐ $ ζ $ 0.4, the rest is w 〇 Example of the present invention is ΑB5 type hydrogen absorbing alloy, wherein the composition of Α is: H18 · 5wt% Ce, 20wt% Pr + Nd, the rest is La; the composition of B5 is: 3.65 moles of Ni, 0.75 moles of Co, 0.31 moles of Mn, and 0.21 moles of A1. The manufacturing method of the hydrogen absorbing alloy of the present invention, please refer to Figs. 1, 2, and 3, including the following steps: 1 · Alloy composition ratio design and materials: φ is the general sABv of the composition of the hydrogen absorbing alloy according to the present invention. Metal elements and appropriate proportions, place the higher melting point metal Fansu in βν alloy near the inner wall of the crucible, and lower melting point metals and elements near the axial centerline of the pin and Position below, and set L m

574375

The metal is placed between a metal with a higher melting point and a metal with a lower melting point to obtain a better chain smelting effect without damaging the inner wall of the hanging steel. 2 · Melt chain treatment: Put the mixture with the alloy composition and design in the heating device to dazzle the chain; the melt chain is in a pressure of less than 5 x 10- Torr (mmHg) and argon Ur) gas atmosphere, At a temperature of 500_165 (rc (Celsius)), continue heating for 30-40 minutes, then cool to 1 200-1 400 ° C, then pour the alloy melt out of the hanging pin, place it in a cooling mold, and evacuate in a vacuum or argon atmosphere. Forced cooling to room temperature (below 40 ° C). 7 3 · Homogenization treatment: Put the hydrogen-absorbing alloy after cooling in a pressure of less than 5 X 1 0M-1 0-2 Torr and gas (Ar) gas atmosphere , At a temperature of 850-1 000 ° c, continue to heat for 2-3 hours, and then naturally cool to room temperature in the same environment. 4 · Micronization treatment: The hydrogen-absorbing alloy after homogenization treatment is crushed, Granulation, milling, sieving and other operations to obtain particles with a size of 74 // m or less, preferably 30-50 &quot; m size for use in nickel-hydrogen batteries. The hydrogen-absorbing alloy obtained by the manufacturing method has high hydrogen absorption, high electric capacity, excellent electrochemical performance, and long life. AB5 type hydrogen absorbing alloy:: 1. particle size: 7 4 // m 2 · scope of the following: etc., as described under Example hereby to AB5 type hydrogen absorbing alloy of the present invention 3C electronic products, power tools, mopeds,

Page 6 574375 V. Description of the invention (4) ~ ~ "一" A rechargeable nickel-metal hydride battery for electric vehicles. 3 · Hydrogen absorption ·· The maximum adsorption capacity when the weight percent concentration of hydrogen absorption is 40 ° C is 1.49wt ° /. (See Figure 4). 4. Electric capacity: 360mAh / g (milliampere hour / gram). 5 · Lifetime: After the nickel-metal hydride battery has been charged and discharged for 5,000 times, its discharge-discharge depth (DOD) is still more than 90%. The main system types for the development of general rare earth hydrogen storage alloys can be summarized as shown in Figure 5; where A is Ca, Y (yttrium), Zr (cool), Ti (titanium) and other metal elements; B, C, D Co, Mn, Al, Fe (iron), Cu (copper),

Metal elements such as Si; Mm is a mixed rare earth metal (Mischmetal) such as La, Ce, Nd, Pr. The composition of the hydrogen storage alloy disclosed in the previous case of the aforementioned patent_ As shown in FIG. 6, it belongs to the third type Mm BU X Ax Ni5-y By-z Cz from the rightmost side of FIG. 5. The composition of the hydrogen absorbing alloy of the present invention is as shown in FIG. 7, which is the design of the inventor improved from the type Mm Ni5-y By-z Cz-w Dw at the far right of FIG. 5 to Lm Niw Cox Mny Alz. The mixed rare earth metal Mm (mischmetal) in the hydrogen absorbing alloy composition of the present invention is replaced with a rhenium-rich mixed rare earth metal Lm (rich-La mischmetal) to increase the hydrogen storage capacity, because the lanthanum content will inevitably increase. However, in order to extend the cycle life of the alloy, the Nd content is increased to achieve the goal; and the amount of pr added and Nd is adjusted within 20% to obtain better initial activity. The alloy group of the present invention is Lm Niw Cox Mny Alz. For best results, it is designed based on ~ = 3 · 65, χ = 0 · 75, y = 0.31, and ζ = 0 · 29, mainly focusing on Mn. Although it can increase the amount of hydrogen stored and reduce the internal pressure of the battery, in the battery, the manganese will gradually dissolve into κ〇 丨 丨 (potassium hydroxide) after the alloy cycles to absorb and release hydrogen

Page 7 574375 V. Description of the invention (5) The alloy is degraded, so the amount of Mn added is reduced to meet the actual application requirements. The addition of f in A 1 is mainly to effectively prevent the alloy from being micronized to reduce the equilibrium pressure (p 1 a t e a u pressure) to meet the needs of practical applications. In addition, Co can effectively extend the life of the alloy but the cost is high. Under the relative conditions that Nd replaces part of La to extend the life of the alloy, the content of Co can be relatively reduced to reduce costs. General hydrogen absorption _ For the manufacture of alloys, after the composition design of the alloy is determined, its structure and shape will be different. Variations, processes or methods will also cause its characteristics to change significantly, & in recent years. Fine design and change control of alloy composition Increasingly refined and accurate, with a view to preparing more efficient hydrogen storage alloys. The hydrogen absorbing alloy of the present invention is different from the type of hydrogen storage alloy disclosed in the previous case. Of course, the composition, characteristics, and functions of the alloy are completely different. The hydrogen absorbing alloy of the present invention does not need to add the hydrogen storage alloy of the previous case. The use of expensive titanium and hafnium metals, but it can make the battery obtain a longer cycle time than the cited case; and this case is more than the previous case. The hydrogen storage alloy has the advantages of simple and early structure and low manufacturing cost. The above is only an embodiment utilizing the technical content of the present invention, and any modifications and changes made by those skilled in the art using the present invention are within the scope of the patent claimed by the present invention and are not limited to those disclosed in the embodiments. In summary, the present invention can obtain a hydrogen absorbing alloy that is simple to manufacture, high hydrogen absorption, high capacity, excellent electrochemical performance, long life, low cost, and commercial value. It has already met the requirements of the invention patent. Patents to _ AirPlus Society.

Claims (1)

1103710 574375-, Λ Round τ years h A hydrogen-absorbing alloy, the general formula of its composition is ABv; its: ff rotten) metal, the wt% (weight percentage) of its composition are: 5-25wi ^ Ce (钸) within 20wt% Pr (镨) And Nd ('), the rest are u 0 (gang); Bv includes metals such as Ni (nickel), c 0 (cobalt), Mn (manganese) & A1 (aluminum), and v is the mole number of b, v Between 4 · 3-5 · 2; Bv, and the general formula is: Ni wCoxMnyA 1 z, v = w + x + y + ζ; where the values of w, x &lt;, y, and zf are: 0.5 $ χ $ 0.85, 0.2 &amp; $ 〇5, 〇1 ~ 〇0.4 The rest is w; its particle size is 74 // m (micrometer) size or less. 2. The hydrogen-absorbing alloy according to item 丨 in the scope of the patent application, wherein the ^ 5, the A, and become 16-168.5wt% Ce, 20wt% pr and Nd, and the rest are La, 4B5 Its composition is 3.65 Moore Ni, 0.75 Moore c0, 0.31 Moore η and 〇29 Moore A1; its particle size is 74 (micrometer ruler) or less.