JPS60230367A - Battery electrode and secondary battery - Google Patents

Abstract

PURPOSE:To prevent dendritic growth of metal to obtain high power by making a battery electrode by forming a porous non-conductive material layer on the surface of a conductive substrate, and immersing it in an electrolyte with a counter electrode to form a secondary battery. CONSTITUTION:A porous non-conductive material layer comprising glass or ceramic is formed on the surface of a conductive substrate comprising metal, carbon, or conductive high polymer compound by surface treatment or bonding to form a battery electrode 2. The electrode 2 is faced with a counter electrode 4 such as a carbon electrode or titanium electrode with a separator 3 interposed, and they are immersed in an electrolyte to form a secondary battery. By performing electrochemical reaction in pores in a porous material layer, and repeating charge and discharge in a range in which deposition of metal is limited in pores, dendritic growth of metal is prevented and high power and high energy density battery can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode for frost and ponds and a secondary battery using the same. The present invention relates to a battery electrode that performs an electrochemical reaction, and a secondary battery composed of the same, a counter electrode, and an electrolyte.

In recent years, with the development and multifunctionality of electronics-related equipment, the demand for high-performance batteries has increased. Among these, lithium batteries have attracted attention for their characteristics of high output and low energy density, and research has been conducted to overcome the high cost of using lithium by converting the batteries into secondary batteries. However, research into making lithium secondary batteries has not been achieved due to the major obstacle of deterioration of the lithium electrode itself due to repeated charging and discharging, and the formation of so-called dendrites. Recently, the development of a lithium secondary battery that suppresses the formation of rainbow dendrite by absorbing lithium in wood metal has been reported, but since wood metal itself is made up of several types of heavy metal alloys, lithium batteries are important. The high energy density, which is a characteristic feature, is sacrificed.

Under these circumstances, the present inventors were conducting research focusing on special Ell electrodes in order to obtain a secondary battery that has the characteristics of high output and high energy density and does not generate dendrites. Forming a porous material layer on the surface,
It was discovered that a secondary battery that satisfies the above requirements could be obtained by utilizing the voids in the layer to carry out an electrochemical reaction,
The invention has been completed.

That is, the present invention provides a battery electrode formed by forming a porous non-conductive material layer on the surface of a conductive substrate, and a secondary battery formed by immersing the electrode and a counter electrode in an electrolytic solution. .

The electrode of the present invention is prepared by treating the surface of a conductive substrate to form a porous non-conductive layer, or by bonding a conductive substrate and a porous material membrane. As the conductive substrate, any material can be used as long as it has conductivity, and examples include metal bars, carbon materials, and conductive cylindrical molecular compounds. In addition, examples of porous non-conductive materials used in the present invention include glass,
All materials that have electrical insulation properties, such as mixes and organic polymer films, are porous or can be made porous. To make the electrode surface porous, it is possible to use the surface porosity technology commonly used at present, such as sintering of fine particles, chemical erosion, electrode scale oxidation, ionization, and Q-tuttering, and the size of the pores is as follows. IOX ~1 mIn% preferably 100X~10 μm. Further, the conductive substrate and the porous non-electric material film are bonded by techniques such as metal vapor deposition, molten maple impregnation, and ion implantation. Among the electrodes prepared in this way, from the viewpoint of reducing the weight of the battery itself, it is preferable to use alumina, organic film, etc. A porous alumina membrane is preferred. In the electrode of the present invention, in principle, it is necessary that the conductive substrate be exposed at the bottom of the hole, but a non-conductive thin film that exhibits substantial electronic conductivity, for example, 30 μm or less, is required. It is acceptable to have an alumina layer with a thickness of .

Further, to construct the secondary battery of the present invention, the above electrode and counter electrode may be immersed in a t-electrolyte.

As the counter electrode, a chargeable and dischargeable electrode such as a carbon electrode, a titanium disulfide electrode, an iron sulfide electrode, a pentoxide electrode, a dinasium electrode, etc. is used. Further, it is prepared by dissolving an electrolyte in a solvent. As an electrode active material for electrolyte,
Although any currently known metals can be used, metals such as alkali metals, zinc, and lead are preferred, particularly metals that easily form dendrites such as lithium and zinc. In addition, counter ions of the electrolyte include perchlorate ion, phosphorus hexafluoride ion, thallium 67 fluoride ion,
Examples include arsenic fluoride ion, antimony hexafluoride ion, halogen ion, nitrate ion, sulfate ion, rhenium tetraoxide ion, and the like.

In addition to water, the solvent used was zolobylene cardanate, γ-butyrolactone, dimethoxyethane, THF.
, dioxane, acetonitrile, and other common solvents for organic batteries.

An example of the structure of the secondary battery of the present invention is shown in FIG. That is, the electrode 2 of the present invention and the counter electrode 4 are placed opposite to each other with the e-lator 3 in between. These electrodes are immersed in electrolyte and sealed.

When charging is performed using the secondary battery of the present invention described above, the electrode active material precipitates only at the bottom of the pores (near the conductive substrate) of the electrode of the present invention that can conduct electrons, and gradually fills the voids from the bottom. Precipitate in a manner that fills the area. Therefore, as long as charging and discharging are repeated within the range where gold droplets are deposited in the voids of the core, it is possible to suppress the formation of dendrites due to concentration of current at the tip and the decrease in charging and discharging efficiency due to lack of precipitated active material. becomes.

Therefore, by using the electrode of the present invention, a battery with high output, high energy density, and no formation of dendrites has become practical.

Next, the present invention will be explained with reference to Examples.

Example 1 High purity aluminum Uno metal (99.99% thickness 100μ
rn) in 0.4 M phosphoric acid at 30 mA/
cm", 140'7 18 minutes), and 10 μm of porous alumina NII was formed on the surface. This electrode (1×
2cIn)′E! Using activated carbon fiber (CH-20, manufactured by Kuraray Chemical Co., Ltd., 2 x 2 m) as a counter electrode,
A battery was constructed using M Li BF4 f robylene carbonate' as the electrolyte. Constant current charge/discharge characteristics of this battery (
Charging at 300 μA for 30 minutes) #i As shown in Figure 2, a stable potential due to charging and discharging of lithium was observed.

When this battery was disassembled after charging and the alumina electrode voids were observed, it was confirmed that lithium metal was deposited uniformly and, as expected, deposited in the alumina voids.

Example 2 High purity aluminum metal (99,991 thickness 30074
m) in 14 wt% sulfuric acid (30 ma/1 wP
50V for 30 minutes) and then apply two porous alumina layers to the surface.
A thickness of 0 μm was formed. This electrode (1×2α) and activated carbon fiber (0H-152X2 manufactured by Kuraray Chemical Co., Ltd.) as a counter electrode
y++) t-m-0, a battery was constructed using 5M Lie 104 propylene carnate as the electrolyte. The constant current charging/discharging cycle characteristics of this battery are shown in FIG.

Example 3゜ Unglazed top 2 mix condenser setter (2nd R
ON-He (manufactured by Nippon Insulator) was thermally sprayed with aluminum on one side to form an electrode. This electrode and activated carbon fiber (0
H-202X21:tn), 1, QMLiBF
An N battery was constructed using 4zolopyrene carnate as an electrolyte.

The constant current charging and discharging characteristics of this battery are as shown in FIG.

[Brief explanation of drawings]

FIG. 1 is a drawing showing an example of the sM of the secondary battery of the present invention. FIG. 2 is a diagram showing the relationship between the time and the voltage between the electrodes when charging and discharging are performed at a constant current (300 μm). FIG. 3 is a diagram showing the relationship between time and voltage between electrodes when charging and discharging are repeated at a constant current (100 μA). FIG. 4 is a diagram showing the relationship between time and voltage between electrodes when charging and discharging at a constant current (500 μA) 1---m-platinum lead wire 2----1 electrode of the present invention 3 -1----Seno Q-lator- 4-----One pair of electrodes 5-----Clip 6-----Teflon plate 7-----Teflon bolt 8--1---Teflon nut Fig. 1 Figure 2 Figure 3

Claims (1)

[Claims] 1. A battery electrode comprising a porous non-conductive material layer formed on the surface of a conductive substrate. 2. The electrode according to claim 1, wherein the porous non-conductive material layer is a porous ceramic layer. The electrode according to claim 1, wherein the porous non-conductive material layer is a sintered body layer of ceramic particles. 4. The electrode according to claim 1, wherein the T4 substrate is an aluminum mold and the porous non-conductive material layer is an alumina layer. 5. A secondary battery comprising an electrode formed by forming a porous non-conductive material layer on the surface of a conductive substrate and a counter electrode immersed in an electrolytic solution. 6. The secondary battery according to claim 5, wherein the counter electrode is any one of a carbon electrode, a titanium disulfide electrode, an iron sulfide electrode, and a panazome pentoxide electrode.