JPS58142771A - Negative electrode for lithium battery - Google Patents

Abstract

PURPOSE:To obtain a negative electrode for a lithium secondary battery which possesses a superior charge and discharge characteristic by using a negative electrode consisting of Li having a LiCl thin film formed. CONSTITUTION:The negative-electrode activating substance is Li, and the positive-electrode activating substance is the substance which carries-out reversible electrochemical reaction with Li ion, and the electrolyte substance is the substance which is stable chemically for the positive-electrode activating substance and Li and suitable for transfer of Li ion for the electrochemical reaction with the positive-electrode activating substance. Li in the form of LiCl is used as the negative electrode used for the Li primary battery and the secondary battery. Formation of LiCl film on an Li surface is achieved by treating the Li metal surface with the compounds containing chlorine. More concretely, the treating method with Cl2 gas, the chemical and electrochemical treating method in use of metal chlorides etc. are listed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lithium negative electrode used in a lithium tank.

Batteries using lithium as a negative active material are being researched as ``batteries'' batteries that are small and have high energy density, but secondaryization has been significant for a long time.

Many compounds and structures have been investigated as positive electrode active structures that can be secondaryized, such as titanium, zirconium, hafnium, niobium, tantalum, vanadium, sulfide, selenide, telluride, etc. A battery cell (as disclosed in U.S. Pat. No. 4,089,052) is disclosed.

However, this kind of second-generation Ikeyoshoshin viscous material
hJF on the charge-discharge characteristics of the LI pole compared to the 1υ1 study.
However, in order to realize Li secondary batteries, the method of manufacturing LI electrodes with good charge/discharge efficiency and cycle life has become a serious issue. .

In an attempt to make the charging and discharging characteristics of Li
Attempt to use i as a negative electrode after gas treatment with Q, Cot 4 (J, Electrochem, Soc,
, voA 125 No. 1371~1377@) and attempts to use an alloy of Li and At as the @ electrode (J, E
electrocham, Soc,, voA12
7.2100 pages to 2x04@3, etc., but they are not necessarily sufficient, and there is a need for the production of Li-choku porridge with excellent timing.

The present invention has been developed in consideration of the above situation, and its purpose is to provide a complete lithium secondary towing pond using the excellent burden of light emission market requirements.

Regarding the present invention, the negative 4-terminus is lithium-2=, and the positive electrode active material is lithium ions and
Jt gas chemically reacts with bamboo, which is chemically constant with respect to Iψ, 11-E, and lithium, and which is chemically constant for lithium and lithium ions. Lichiwam number who was pregnant with the first active proboscis and electrification reaction / ζ
This is an additional characteristic of kokeno.

If lithium such as lithium gold pJ4A & etc. is used in vain as lithium negative 41, it will cause discharge or charging.
, (rlT) increases due to local reaction promotion,
Phenomena such as holes forming in the lithium negative sliding door and tendritic lithium precipitated during charging and dissolving from the 1〆λ occur. It is thought that this causes a decrease in the charging and discharging efficiency of Li 1ffi, and forms a qualitative film of photodischarge of lithium, as shown in the above-mentioned "Example 1-1". .

3- 1 on the lithium surface. The method for forming a thin film of ICT is as follows:
In the present invention, it is limited to 5i-,: tL, which is a compound that subsides a complex. 14
Physically ljl, treated with Cl3 gas 11) 51/c Chemically and electrochemically ζ, processed metal! The method of using 14th class [Mi] is deeply humiliated.

Below is a detailed explanation of non-invention using -)4.

Here, the treatment method for 11.41 lithium is an example,
There is no restriction on Pt6.

Actual example] A lithium flake (II!-0.5 m
J ′a1 clause 4 and product (-) all, positive electrode and 1 ~ te pt several digits, tun I ill night as propyLy7 carbonail l□ (
]) C) Nol, 1c7y'@Il1g liquid i was assembled into a cell, and the constant ImA/c7I flowed between 114 and 12 juices, and the lithium was used as the opposite sex, as an action stool. Use p t as the reference pole and r l) Assemble a new Selke using Tyranno\ and make 1 word 4 on the Pt pole: By J4, ■71. (Charge/discharge student) Sex I: I trained 7 days ago. L crazy l
111 Liquid Shiko V, Ding, 2NLiC/:04/PC was used.

The measurement was carried out at a constant current of 1 mA/cd for 1 minute at P
t4- After depositing El i on pole-H and charging, 1 mA/cr
A cycle test was conducted in which Li deposited on a Pt layer was discharged with Lt ions at a constant flow rate of I. The charging and discharging efficiency was determined from the potential change of Pt *, and was determined by the electric flux required to discharge the Li, + deposited on the Pt proboscis J- as Ll ions [7] and the electrical flux required to deposit Lx on the Pt top. It was calculated from the ratio of

FIG. 1 is a diagram showing the relationship between the charging/discharging efficiency of the El electrode and the number of cycles, and (a) in the figure shows the case where the LAC1-treated LAC1 treated under the above conditions is used as the Li negative electrode. (b
) shows the charging and discharging characteristics of ■, ■, and negative when an Ll thin piece (untreated) is used as the Li@ pole in a conventional example. As can be seen from Figure 1, LiCt is used as a lithium negative electrode.
By using 17-treated lithium, the charge-discharge characteristics of Li keyaki are significantly improved.

Example 2 The charge-discharge characteristics of Li were determined in the same manner as in Example 1, except that lithium was charged with a propylene carbonate solution of Lict for 23 minutes at 1 mA/cII as lithium negative. It was measured.

5- Figure 2 is a diagram showing the relationship between the charge/discharge efficiency of Li fdi and the number of cycles, and (a) in the figure shows Lt44 of the present invention, which was treated with LiCt under the above conditions. (b) is the case where L is used as the negative electrode of the sample T-y t
Figure 2 shows the charging and discharging % properties of ■ and i* when using a t-thin section (non-91 attack).As can be seen from Figure 2, 41 As a result, the charge/discharge characteristics of Li electrodes have been significantly improved [7].

Particularly, as is clear from the above description, according to the present invention, a negative electrode for a lithium secondary battery with excellent charge/discharge characteristics can be realized by using lithium with a Ltcz, ti1 film formed thereon as a negative electrode.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are diagrams showing the relationship between the charging and discharging efficiency of the lithium electrode and the number of cycles according to an embodiment of the present invention. Applicant's agent Tadashi Yamamiya Lee 61

Claims (1)

[Claims] A negative electrode for a lithium battery, characterized in that the surface of lithium metal is treated with a compound containing chlorine to form LiC4 on the surface.