JPS6261273A - Hydrogen solid battery - Google Patents

Abstract

PURPOSE:To obtain a hydrogen solid battery having a superior charge-and- discharge characteristic by using a material principally composed of a molybdenum oxide to make the positive electrode. CONSTITUTION:The positive electrode of the hydrogen solid battery of this invention is principally composed of a molybdenum oxide (MoO3-x: 0<=x<=0.3). Use of a molybdenum oxide in the positive electrode achieves production of a hydrogen solid battery which has superior charge-and-discharge performance and can be repeatedly charged and discharged.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a positive electrode for a solid-state hydrogen battery in which a negative electrode active material, an electrolyte, and a camellia active material are all solid.

<Prior art> With the recent development of live conductor technology and its application technology,
The power consumption of electronic devices is gradually decreasing. In addition, batteries used in these electronic devices are desired to be smaller and thinner with lower power consumption, and at the same time, they are also required to be highly reliable. Solid electrolyte batteries meet these demands. Solid electrolyte batteries use a solid containing ionic conductors as the electrolyte;
There is no liquid leakage from the pond, and mass production is easy.

Conventionally, silver, copper, and lithium-based batteries have been developed as such solid electrolyte batteries. Among these, batteries using silver ions or copper ions have the property that the ionic conductivity of the solid electrolyte is relatively high and discharge at a large current is possible. Although lithium-based solid electrolyte batteries have high energy density and high output voltage, they cannot be discharged with large currents because the ionic conductivity of the solid electrolyte used is not very high. In addition, since lithium metal is extremely active, the battery manufacturing process and sealing technology are complicated due to oxidation and moisture resistance. Furthermore, in any of the above solid-state batteries, when considering the use of secondary batteries, the 4-electrode species that are reduced at the negative electrode precipitate in a dendritic form during charging, resulting in poor cycle life and the inability to perform deep discharge. Big problems remain.

<Summary of the Invention> The present invention provides a hydrogen solid battery by configuring the negative electrode with a hydrogen-absorbing alloy, the electrolyte with a hydrogen ion-conducting species (an interstitial electrolyte), and the positive electrode with a substance that accepts 1/l of hydrogen ions. Based on this, we have made full use of the unique technology of +E pole. In the case of a solid-state hydrogen battery, it is a diffusion-type electrode in which only the diffusion of hydrogen leads to a reaction, so unlike conventional precipitation-type electrodes that use metal ions as conductive species, the hydrogen is generated by repeated charging and discharging. No dendritic precipitates;
It is characterized by good repeatability of charging and discharging. An object of the present invention is to provide such a solid hydrogen battery with a good charge/discharge performance of 1 Jt.

<Description of Structure and Effects> An alloy that absorbs hydrogen in the form of a metal hydride remains solid even in the hydrogen-absorbed state. Hydrogen storage alloys contain elements (Mg, Ca) that absorb hydrogen.

(La, Ti, V, etc.) and hydrogen as antecedents.
By combining these elements (Fe, Co, Ni+ Cu, etc.), materials with various dissociation pressures and occlusion properties can be realized. This hydrogen storage alloy is used as a negative electrode.

Antimony pentoxide (Sb205@
Hydrogen ion conductive oxides such as nHo), tin dioxide (Sn02-nl+2o), and solid polymer electrolytes such as perfluorocarbons are used. In addition, as the electrode material, a substance that accepts hydrogen ions as a guest substance is used. Using the above materials, a battery is constructed, for example, as shown in Figure 1. In Figure 1, l is the negative electrode, and 2 is the negative electrode. A solid electrolyte, 3 is an IL electrode, 4 is a current collector, 5 is a lead wire, 6 is a pressure plate, and 7 is a screw.The potential of this battery varies depending on the negative electrode material and positive electrode material used.The present invention is directed to this positive electrode. Molybdenum oxide (MoOa -X: O≦X≦0
As a result of examining various electrode materials characterized by the use of 3) as a component, we found that by using molybdenum oxide as the positive electrode material, a battery with the best discharge characteristics and the ability to be repeatedly charged and discharged was realized. It was clarified that this would happen.

<Example> An example of the present invention will be described in detail below with reference to the 11th Q. Commercially available titanium (995% purity) and nickel (
(purity 9995%) and Mitsushmetal in atomic ratio]:
] : Weigh and mix so that it becomes 0.01.

This is melted in an arc melting furnace. This alloy is placed in a stainless steel container, high-pressure hydrogen gas is introduced, and hydrogenation is achieved by heating. That is, it is a hydrogen storage alloy. The hydrogenated alloy is taken out and ground to a particle size of 447 zm or less in an argon gas atmosphere. 02 g of this powder, 0.01 g of carboxymethyl cellulose powder, 001 g of acetylene black, and 005 g of a solid electrolyte to be described later are mixed and made into pellets using a tablet molding machine. This will be referred to as negative electrode 1.

Next, antimony pentachloride (SbCt5) is dropped into pure water, and the resulting precipitate is washed and dried to obtain antimony pentoxide. Weigh 02g of this and make it into pellets using a tablet molding machine. As described above, the solid electrolyte 2 is composed of antimony pentoxide, which is a hydrogen ion conductive oxide.

Next, ammonium molybdate tetrahydrate ((NFI4
)6Mo7024.4I■20) is dissolved in pure water, heated, and then hot nitric acid is added dropwise, and the resulting precipitate is washed and dried to obtain molybdenum oxide (MoOa). This molybdenum oxide 02g1 carboxymethyl cellulose powder 0.0
Weigh 1 gl of acetylene black (12 g) and 0.05 g of the above-mentioned solid electrolyte; ii. Mix and pelletize using a tablet machine. This is made into a 11゛ electrode 3〇These negative electrode 11 electrolyte 2 and positive electrode 3 are stacked together, sandwiched between a current collector plate 4 and a pressure plate 6, and fixed with screws 7' to form a hydrogen solid battery. The electric body 4 makes good contact between the positive electrode 3 and the negative electrode 1 and the external connection lead wire 5. This is the first hydrogen solid state battery in this example! 11 open-circuit potential was 420 mV.

In order to investigate the performance of the hydrogen solid state battery produced as described above, I= l O07! The discharge was carried out at a current density of A/cn. The discharge characteristics at this time are shown in FIG. As is clear from the special 1/T curve, the discharge pressure remains almost constant even after 90 hours have passed after the start of discharge, indicating that the battery characteristics are good (
I got hit. Next, 50 lt batteries were prepared in the same manner.
A charge/discharge test was conducted in which charging and discharging were repeated every 2 hours at a current density of A/crI. The results are shown in FIG. Even after repeating the charge/discharge operation 10 times, the ease curve hardly changes.As is clear from Figures 2 and 3, using molybdenum oxide as the positive electrode, VC
-Practical as a secondary battery and as a secondary jI [ii pond]
A hydrogen solid-state battery with very good charging and discharging capacity of 44 times is obtained.

In addition, Mo8023, "40Il" was used as the positive electrode material.
For f, the open circuit potential after battery fabrication is 280, respectively.
rnV.

The voltage was 410 mV, indicating a similarly good discharge time.

In addition to the above, Mo9026 is also used as the iF, pole material *-1.
A divine molybdenum oxide such as 1M0028 can be used.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a hydrogen solid state battery used to explain embodiments of the present invention.
5. -0 ￥lError It is a discharge characteristic diagram of a hydrogen solid state battery according to an example. No. 31, No. 1 is a chart showing 44 cases of charging and discharging a hydrogen lid battery according to an embodiment of the present invention.

Claims (1)

[Scope of Claims] 1. A solid hydrogen battery in which the negative electrode is made of a metal hydride which is a hydrogen storage material that stores hydrogen, the solid electrolyte is a hydrogen ion conductor, and the positive electrode is made of a material that can accept hydrogen ions. is molybdenum oxide (MoO_3_-
_x) (0≦x≦0.3). 2. Molybdenum oxides are MoO_3, Mo_9O_2_
6, Mo_8O_2_3, Mo_4O_1_1 or Mo
O_2_. The hydrogen solid state battery according to claim 1, which is _8.