Electrospinning for integrated separator for lithium-ion batteries

• US 9,065,122 B2
• Filed: 09/02/2011
• Issued: 06/23/2015
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Orilall, Mahendra C., Talwar, Raman, Brown, Karl M., Yang, Lu, Bolandi, Hooman, Pebenito, Victor, Wang, Connie P., Bachrach, Robert Z.
• Primary Examiner(s): BEST, ZACHARY P
• Application Number:
  US13/224,709
• Publication Number:
  US 20120082884A1
• Time in Patent Office: 1,390 Days
• Field of Search: 429/247, 429/249, 429/251
• US Class Current: 1/1
• CPC Class Codes: B05B 5/0255 spraying and depositing by electrostatic forces only
• CPC Class Codes: D01D 5/0084 Coating by electro-spinning, i.e. the electro-spun fibres are not removed from the collecting device but remain integral with it, e.g. coating of prostheses
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2220/10 Batteries in stationary systems, e.g. emergency power source in plant
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: 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
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: 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
• CPC Class Codes: H01M 4/5815 Sulfides
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 50/403 Manufacturing processes of separators, membranes or diaphragms
• CPC Class Codes: H01M 50/42 Acrylic resins
• CPC Class Codes: H01M 50/423 Polyamide resins
• CPC Class Codes: H01M 50/434 Ceramics
• CPC Class Codes: H01M 50/44 Fibrous material
• CPC Class Codes: H01M 50/451 comprising layers of only organic material and layers containing inorganic material
• CPC Class Codes: H01M 50/491 Porosity
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Embodiments of the present invention relate generally to lithium-ion batteries, and more specifically, to batteries having integrated separators and methods of fabricating such batteries. In one embodiment, a lithium-ion battery having an electrode structure is provided. The lithium-ion battery comprises an anode stack, a cathode stack, and a porous electrospun polymer separator comprising a nano-fiber backbone structure. The anode stack comprises an anodic current collector and an anode structure formed over a first surface of the anodic current collector. The cathode stack comprises a cathodic current collector and a cathode structure formed over a first surface of the cathodic current collector. The porous electrospun polymer separator is positioned between the anode structure and the cathode structure.

Claims

1. A method of forming an electrode structure comprising:

electrospinning a nano-fiber backbone structure having embedded ceramic particles directly onto a surface of a first electrode structure to form a porous electrospun polymer separator, wherein electrospinning the nano-fiber backbone structure comprises;

depositing a polymer containing liquid mixture onto a surface parallel to the surface of the first electrode structure, wherein the polymer containing liquid mixture comprises the ceramic particles; and

applying a voltage to the polymer containing liquid mixture to electrospin the nano-fiber backbone structure embedded with the ceramic particles onto the surface of the first electrode structure; and

electrospraying a second polymer material over the nano-fiber backbone structure having embedded ceramic nanoparticles.

2. The method of claim 1, wherein the nano-fiber backbone structure comprises a first polymer material selected from poly(acrylic acid) (PAA), polyvinylidene fluoride (PVDF), carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR).

4. The method of claim 2, wherein the ceramic particles are selected from the group of:

Pb(Zr,Ti)O₃ (PZT), Pb_1-xLa_xZr_1-yTi_yO₃ (PLZT, x and y are independently between 0 and

     1), PB(Mg₃Nb_2/3)O₃—

PbTiO₃ (PMN-PT), BaTiO₃, HfO₂ (hafnia), SrTiO₃, TiO₂ (titania), SiO₂ (silica), Al₂O₃ (alumina), ZrO₂ (zirconia), SnO₂, CeO₂, MgO, CaO, Y₂O₃ and combinations thereof.

5. The method of claim 1, wherein

the first polymer material has a high melting temperature greater than 200°

C.; and

wherein the second polymer material has a low melting temperature less than 140°

C. and forms a plurality of low melting temperature polymer lines in the porous electrospun polymer separator, such that during a thermal runaway, the low melting temperature polymer lines are melted and fused together, reducing a porosity in the porous electrospun polymer separator and thus slowing a lithium-ion transport and one or more associated electrochemical reactions.

6. The method of claim 1, wherein the ceramic particles have a diameter between about 10 nm and about 20 nm.

7. The method of claim 1, wherein the ceramic particles are added to the polymer containing liquid mixture using a sol-gel process.

8. The method of claim 1, further comprising:

ultrasonically agitating the polymer containing liquid mixture before the voltage is applied to the polymer containing liquid mixture.

9. The method of claim 1,

wherein the second polymer material is selected from polyvinylidene fluoride (PVDF), carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR).

3. A method of forming an electrode structure comprising:

electrospinning a nano-fiber backbone structure directly onto a surface of a first electrode structure to form a porous electrospun polymer separator, wherein the nano-fiber backbone structure comprises a first polymer material selected from poly(acrylic acid) (PAA), polyvinylidene fluoride (PVDF), carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR); and

electrospraying a second polymer material over the nano-fiber backbone structure wherein the second polymer material is selected from polyvinylidene fluoride (PVDF), carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR).