# US 12,009,504 B2 · Electrode, electrode group, secondary battery, battery pack, and vehicle

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- Number: US 12,009,504 B2
- Document ID: US12009504B2
- Status: Granted
- Kind: B2
- Application number: 17/186,046
- Filed: 2021-02-26
- Published: 2022-03-17
- Granted: 2024-06-11
- Earliest claimed: 2020-09-17
- Assignees: Kabushiki Kaisha Toshiba
- Applicants: Kabushiki Kaisha Toshiba
- Inventors: Yasunobu Yamashita; Keigo Hoshina; Yasuhiro Harada; Norio Takami; Shinsuke Matsuno
- Web page: https://patentgrep.com/patent/US12009504B2

## CPC

- H01M 4/362: {Composites}
- H01M 10/052: Li-accumulators
- H01M 4/485: of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence)
- H01M 4/625: {Carbon or graphite}
- H01M 10/0413: {Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes}
- H01M 10/0431: {Cells with wound or folded electrodes (H01M10/045 takes precedence)}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 10/0587: of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
- B60L 50/64: Constructional details of batteries specially adapted for electric vehicles
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/027: {Negative electrodes}
- H01M 2220/20: Batteries in motive systems, e.g. vehicle, ship, plane
- 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
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- 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

According to one embodiment, provided is an electrode including a current collector and an active material-containing layer in contact with the current collector. The active material-containing layer contains a carbon nanotube and particles of titanium-containing oxide having an average particle size or 0.1 μm to 3 μm. A peel strength between the current collector and the active material-containing layer is within a range of 0.2 kN/m to 0.7 kN/m.

## Claims

### Claim 1

An electrode group comprising:
a positive electrode; and
a negative electrode,
the electrode group having a wound structure of a flat shape where a stack comprising the positive electrode and the negative electrode is wound in a manner where a center of the wound structure lies along a first direction,
wherein the negative electrode comprises:
a current collector; and
an active material-containing layer in contact with the current collector, the active material-containing layer comprising a carbon nanotube and titanium-containing oxide particles having an average particle size of 0.1 μm to 3 μm,
a peel strength between the current collector and the active material-containing layer according to a surface/interface cutting method is from 0.2 kN/m to 0.7 kN/m, and
a part of the active material-containing layer of the negative electrode is in an unbound state with respect to the current collector at an innermost bent section positioned innermost in the wound structure, the unbound state being a state where an interspace is present between the current collector and the active material-containing layer or where the current collector and the active material-containing layer are in contact with each other but not bound to each other.

### Claim 2 (depends on 1)

The electrode group according to claim 1, wherein for the active material-containing layer in the innermost bent section, an unbound ratio is from 1% to 20% per unit area of a width of 1 cm and a height of 5 cm, centered on the innermost bent section, where the unbound ratio is an area ratio of an area of a portion where the active material-containing layer is unbound to a total area of the unit area.

### Claim 3 (depends on 1)

The electrode group according to claim 1, wherein the titanium-containing oxide comprises one or more selected from the group consisting of lithium titanate having a spinel structure; monoclinic titanium dioxide; orthorhombic titanium-containing composite oxide represented by Li2+aMα2−bTi6−cMβdO14+σ where Mα is at least one selected from the group consisting of Sr, Ba, Ca, Mg, Na, Cs, Rb and K, Mβ is at least one selected from the group consisting of Zr, Sn, V, Nb, Ta, Mo, W, Y, Fe, Co, Cr, Mn, Ni and Al, 0≤a≤6, 0≤b<2, 0≤c<6, 0≤d<6, and −0.5≤σ<0.5; and monoclinic niobium-titanium composite oxide represented by LixTi1−yM1y+zNb2−zO7−δ where, M1 is at least one selected from the group consisting of Mg, Fe, Ni, Co, W, Ta, and Mo, 0≤x≤5, 0≤y<1, 0≤z<2, and −0.3≤δ≤0.3.

### Claim 4 (depends on 1)

The electrode group according to claim 1, wherein the current collector is made of copper, nickel, stainless steel, aluminum, or an aluminum alloy including one or more selected from the group consisting of Mg, Ti, Zn, Mn, Fe, Cu, and Si.

### Claim 5 (depends on 1)

The electrode group according to claim 1, wherein the active material-containing layer contains an electro-conductive agent comprising the carbon nanotube or the carbon nanotube and one or more selected from the group consisting of vapor grown carbon fiber, acetylene black, and graphite.

### Claim 6 (depends on 1)

The electrode group according to claim 1, wherein the active material-containing layer further contains one or more binder selected from the group of polytetrafluoroethylene, polyvinylidene fluoride, fluororubber, styrene-butadiene rubber, polyacrylate compounds, imide compounds, carboxymethyl cellulose, and salts of carboxymethyl cellulose.

### Claim 7 (depends on 1)

The electrode group according to claim 1, wherein the active material-containing layer contains an active material comprising the titanium-containing oxide, an electro-conductive agent comprising the carbon nanotube, and a binder, and the active material-containing layer contains the active material in a proportion of 70% by mass to 96% by mass to the active material-containing layer, the electro-conductive agent in a proportion of 2% by mass to 28% by mass to the active material-containing layer, and the binder in a proportion of 2% by mass to 10% by mass to the active material-containing layer.

### Claim 8 (depends on 1)

A secondary battery comprising:
the electrode group according to claim 1; and
an electrolyte.

### Claim 9 (depends on 8)

A battery pack comprising the secondary battery according to claim 8.

### Claim 10 (depends on 9)

The battery pack according to claim 9, further comprising an external power distribution terminal and a protective circuit.

### Claim 11 (depends on 9)

The battery pack according to claim 9, comprising plural of the secondary battery, the secondary batteries being electrically connected in series, in parallel, or in combination of in-series connection and in-parallel connection.

### Claim 12 (depends on 9)

A vehicle comprising the battery pack according to claim 9.

### Claim 13 (depends on 12)

The vehicle according to claim 12, wherein the vehicle comprises a mechanism configured to convert kinetic energy of the vehicle into regenerative energy.