Positive electrode for non-aqueous electrolyte secondary battery, non-aqueous electrolyte secondary battery and battery module

Patent metadata

Field	Value
Publication number	US-9960416-B2
Application number	US-201113993901-A
Country	US
Kind code	B2
Filing date	Dec 14, 2011
Priority date	Dec 17, 2010
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

The present invention provides a positive electrode for a non-aqueous electrolyte secondary battery in which the charge/discharge rate of a secondary battery is increased by increasing the discharge/discharge rate of the positive electrode as a result of increasing the rate of incorporation and release of lithium ions in olivine-type phosphorous complex compound particles, a non-aqueous electrolyte secondary battery provided with this positive electrode for a non-aqueous electrolyte secondary battery, and a battery module provided with this non-aqueous electrolyte secondary battery. The positive electrode for a non-aqueous electrolyte secondary battery of the present invention is a positive electrode for a non-aqueous electrolyte secondary battery containing olivine-type lithium complex compound particles having a carbonaceous film formed on the surface thereof as a positive electrode active material, in which the coverage factor of the carbonaceous film relative to the surface area of the olivine-type lithium complex compound particles is preferably 95% or more, and the packed density of the olivine-type lithium complex compound particles in this positive electrode for a non-aqueous electrolyte secondary battery is preferably 0.90 g/cm 3 to 1.09 g/cm 3 .

First claim

We claim:

1. A positive electrode for a non-aqueous electrolyte secondary battery containing a positive electrode active material layer, wherein the positive electrode active material layer comprises a binder, a conductive material, and olivine-type lithium complex compound particles, wherein:
a carbonaceous film is formed on the surface of the particles,
the coverage factor of the carbonaceous film relative to the surface area of the olivine-type lithium complex compound particles is 95% or more, and the coverage factor is measured after a uniform mixture of the binder, the conductive material and the olivine-type lithium complex compound particles is prepared to form the positive electrode active material layer,
the carbonaceous film consists of amorphous carbon, and
the packed density of the olivine-type lithium complex compound particles in the layer is 0.90 g/cm 3 to 1.09 g/cm 3 , wherein the packed density is a value obtained by the following formula:
packed density of olivine-type lithium complex compound particles in the layer =(weight of the olivine-type lithium complex compound particles in the layer) / (volume of the layer).

2. A non-aqueous electrolyte secondary battery provided with the positive electrode for a non-aqueous electrolyte secondary battery according to claim 1 .

3. A battery module provided with the non-aqueous electrolyte secondary battery according to claim 2 .

4. A non-aqueous electrolyte secondary battery that uses a positive electrode containing a carbon-coated, olivine-type lithium complex compound as a positive electrode active material, wherein the positive electrode has a positive electrode active material layer containing 4 parts by weight to 6 parts by weight of a conductive material and 4 parts by weight to 8 parts by weight of a binder based on 100 parts by weight of the positive electrode active material, and the carbon coverage area ratio of the carbon-coated, olivine-type complex compound particles is 95% or more, and wherein the coverage area is measured after a uniform mixture of the binder, the conductive material and the olivine-type lithium complex compound particles is prepared to form the positive electrode active material layer;
the packed density of the olivine-type lithium complex compound particles in the layer is 0.90 g/cm 3 to 1.09 g/cm 3 , wherein the packed density is a value obtained by the following formula:
packed density of olivine-type lithium complex compound particles in the layer =(weight of the olivine-type lithium complex compound particles in the layer) / (volume of the layer).

5. A battery module comprising connecting a plurality of the non-aqueous electrolyte secondary batteries according to claim 4 .

6. A battery module provided with the non-aqueous electrolyte secondary battery according to claim 2 .

7. A battery module comprising a plurality of the non-aqueous electrolyte secondary batteries according to claim 2 .

8. The positive electrode for a non-aqueous electrolyte secondary battery according to claim 1 , wherein the coverage factor is measured with a scanning electron microscope or energy-dispersive X-ray spectroscopy using observation samples, wherein the observation samples are obtained by:
immersing a portion of the positive electrode active material layer in a solvent to dissolve the binder and separate particles of the positive electrode active material as the observation samples, or
removing a portion of the positive electrode active material layer to extract particles of the positive electrode active material as the observation samples.

Assignees

• Hara Tomitaro
• Fukunaga Takao
• Iguchi Takayasu
• Kitagawa Takao
• Yamamoto Yoshitaka
• Sumitomo Osaka Cement Co Ltd

Inventors

• Hara Tomitaro
• Fukunaga Takao
• Iguchi Takayasu
• Kitagawa Takao
• Yamamoto Yoshitaka

Classifications

• H01M2010/4292

  Aspects relating to capacity ratio of electrodes/electrolyte or anode/cathode · CPC title

• H01M10/42

  Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells (H01M10/60 takes precedence) · CPC title

• H01M4/13

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M50/20

  Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders (structural combination of accumulators with charging apparatus H01M10/46) · CPC title

• H01M4/366 Primary

  as layered products · CPC title