# US 2019/0356014 A1 · A lithium ion secondary battery and a method for producing the same

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- Number: US 2019/0356014 A1
- Document ID: US20190356014A1
- Status: Published application
- Kind: A1
- Application number: 16/331,276
- Filed: 2017-08-28
- Published: 2019-11-21
- Earliest claimed: 2016-09-08
- Assignees: Maxell Holdings, Ltd.
- Applicants: Maxell Holdings, Ltd.
- Inventors: Hiroshi Abe; Susumu Yoshikawa; Tomohito Sekiya
- Web page: https://patentgrep.com/patent/US20190356014A1

## CPC

- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 4/366: {as layered products}
- H01M 4/483: {for non-aqueous cells (H01M4/485 takes precedence)}
- H01M 4/505: of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
- H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
- H01M 10/0569: characterised by the solvents
- H01M 50/414: Synthetic resins, e.g. thermoplastics or thermosetting resins
- H01M 50/417: Polyolefins
- H01M 50/446: Composite material consisting of a mixture of organic and inorganic materials
- H01M 50/451: comprising layers of only organic material and layers containing inorganic material
- H01M 50/491: Porosity
- H01M 2220/30: Batteries in portable systems, e.g. mobile phone, laptop
- H01M 2300/0037: Mixture of solvents
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

The lithium ion secondary battery includes an electrode body and a nonaqueous electrolyte liquid. The negative electrode active material in the negative electrode includes a materials S including Si. Assuming that a total of all negative electrode active materials included in the negative electrode is 100 mass %, a content of the material S is higher than 5 mass %. The nonaqueous electrolyte liquid comprises propylene carbonate and a chain carbonate as a solvent. A volume content of the propylene carbonate in the solvent is 10 to 50 volume %. The positive electrode comprises a positive electrode composition layer comprising a metal oxide comprising Li and a metal M except for Li as a positive electrode active material provided on at least one surface of a positive electrode current collector. The lithium ion secondary battery has an upper limit voltage in charge is 4.35 V of more.

## Claims

### Claim 1

A lithium ion secondary battery, comprising: an electrode body comprising a positive electrode, a negative electrode and a separator therebetween which are stacked or wound; and a nonaqueous electrolyte liquid,
wherein the negative electrode has a negative electrode composition layer mainly composed of a negative electrode active material provided on at least one surface of a negative electrode current collector, the negative electrode active material including a materials S including Si,
wherein assuming that a total of all negative electrode active materials included in the negative electrode is 100 mass %, a content of the material S is 5 mass % or more,
wherein the nonaqueous electrolyte liquid comprises propylene carbonate and a chain carbonate as a solvent,
wherein a volume content of the propylene carbonate in the solvent is 10 to 50 volumes %,
wherein the positive electrode comprises a positive electrode composition layer comprising a metal oxide comprising Li and a metal M except for Li as a positive electrode active material provided on at least one surface of a positive electrode current collector, and
wherein the lithium ion secondary battery has an upper limit voltage in charge is 4.35 V of more.

### Claim 2 (depends on 1)

The lithium ion secondary battery according to claim 1,
wherein the positive electrode comprises a positive electrode material in which a surface of particles of the positive electrode active material is coated with an Al-containing oxide,
wherein the Al-containing oxide has an average coating thickness of 5 to 50 nm,
wherein the positive electrode active material contained in the positive electrode material comprises a lithium cobalt oxide comprising Co and at least one kind of an element M1 selected from the group consisting of Mg, Zr, Ni, Mn, Ti and Al.

### Claim 3 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the material S is a negative electrode material comprising SiOx including Si and O as constituent elements (wherein an atom ratio x of the O with respect to the Si is 0.5≤x≤1.5).

### Claim 4 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein at the time when the lithium ion secondary battery is discharged at an discharge current rate of 0.1 C to reach a voltage of 2.0 V, a molar ratio (Li/M) of the Li and the metal M except for the Li contained in the positive electrode active material is 0.8 to 1.05.

### Claim 5 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the separator comprises a porous membrane (I) mainly composed of a thermoplastic resin, and a porous layer (II) mainly composed of fillers having a heat resistant temperature of 150° C. or more.

### Claim 6 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the the lithium ion secondary battery further comprises a third electrode to insert Li ions into the negative electrode,
wherein the third electrode is disposed at least at an end face of the electrode body stacked such that the third electrode is electrically conductive with the negative electrode.

### Claim 7 (depends on 1)

The lithium ion secondary battery according to claim 1, wherein the negative electrode has been made of the negative electrode composition layer including the negative electrode active material not including Li, the negative electrode composition layer being doped with Li ions.

### Claim 8 (depends on 6)

A method for producing the lithium ion secondary battery according to claim 6, comprising:
using the third electrode having a Li supply source; and
electrically connecting the third electrode with the negative electrode to insert Li ions into the negative electrode.

### Claim 9 (depends on 7)

A method for producing the lithium ion secondary battery according to claim 7, comprising:
providing the negative electrode having the negative electrode composition layer comprising a material not including Li and a binder;
doping the negative electrode composition layer with Li ions; and
then using the negative electrode to manufacture the lithium ion secondary battery.

### Claim 10 (depends on 2)

The lithium ion secondary battery according to claim 2, wherein at the time when the lithium ion secondary battery is discharged at an discharge current rate of 0.1 C to reach a voltage of 2.0 V, a molar ratio (Li/M) of the Li and the metal M except for the Li contained in the positive electrode active material is 0.8 to 1.05.