Method of producing granular aggregate, method of producing electrode plate, and method of producing battery

Patent metadata

Field	Value
Publication number	US-10897036-B2
Application number	US-201715808129-A
Country	US
Kind code	B2
Filing date	Nov 9, 2017
Priority date	Nov 21, 2016
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

A method of producing a granular aggregate in which wet granulated substances including active material particles, conductive material particles, a binding agent for binding the active material particles and the conductive material particles, and a solvent are aggregated includes adding a binding agent solution in which the binding agent is dissolved in the solvent to the active material particles having a solvent absorbing property, mixing the binding agent solution and the active material particles such that a primary granular aggregate in which granulated primary granulated substances are aggregated is produced, and mixing the conductive material particles into the primary granular aggregate and producing a granulated granular aggregate.

First claim

What is claimed is:

1. A method of producing a granular aggregate in which wet granulated substances including active material particles, conductive material particles, a binding agent for binding the active material particles and the conductive material particles, and a solvent are aggregated, the method comprising:
dissolving the binding agent in the solvent to obtain a binding agent solution;
adding the binding agent solution to the active material particles having a solvent absorbing property,
performing a primary granulation step of granulating the binding agent solution and the active material particles to obtain a wet primary granular aggregate in which wet primary granulated particulates are aggregated; and
mixing the conductive material particles into the wet primary granular aggregate; and
performing a secondary granulation step of granulating the conductive material particles and the wet primary granular aggregate to obtain a granulated granular aggregate,
wherein a particle size of the granulated granular aggregate is several tens of μm to several mm, and
a solid fraction in the granulated granular aggregate is 76.0 wt % to 80 wt %.

2. The method of producing a granular aggregate according to claim 1 ,
wherein the active material particles are porous active material particles formed by aggregation of primary particles made of an active material.

3. The method of producing a granular aggregate according to claim 2 ,
wherein the active material particles are porous positive electrode active material particles made of a lithium-containing positive electrode active material, the conductive material particles are acetylene black, the binding agent is polyvinylidene fluoride, and the solvent is N-methyl-2-pyrrolidone.

4. A method of producing an electrode plate including a current collecting plate and an active material layer, the method comprising:
transferring the granular aggregate produced by the method according to claim 1 to the current collecting plate such that an undried active material layer is formed; and
drying the formed undried active material layer.

5. A method of producing a battery, comprising:
forming an electrode body including the electrode plate produced by the method according to claim 4 ;
accommodating the electrode body in a battery container;
injecting an electrolyte solution into the battery container; and
sealing the battery container.

Assignees

• Toyota Motor Co Ltd

Inventors

• Akiyama Naohisa

Classifications

• H01M50/636

  Closing or sealing filling ports, e.g. using lids · CPC title

• B01F27/171

  for disintegrating, e.g. for milling · CPC title

• B01F35/221422

  Speed of rotation of the mixing axis, stirrer or receptacle during the operation · CPC title

• B01F27/1123

  sickle-shaped, i.e. curved in at least one direction · CPC title

• B01F35/2209

  Controlling the mixing process as a whole, i.e. involving a complete monitoring and controlling of the mixing process during the whole mixing cycle · CPC title