Lithium ion batteries comprising nanofibers

Patent metadata

Field	Value
Publication number	US-2018331341-A1
Application number	US-201816035823-A
Country	US
Kind code	A1
Filing date	Jul 16, 2018
Priority date	Mar 2, 2012
Publication date	Nov 15, 2018
Grant date	—

Abstract

Lithium ion batteries, electrodes, nanofibers, and methods for producing same are disclosed herein. Provided herein are batteries having (a) increased energy density; (b) decreased pulverization (structural disruption due to volume expansion during lithiation/de-lithiation processes); and/or (c) increased lifetime. In some embodiments described herein, using high throughput, water-based electrospinning process produces nanofibers of high energy capacity materials (e.g., ceramic) with nanostructures such as discrete crystal domains, mesopores, hollow cores, and the like; and such nanofibers providing reduced pulverization and increased charging rates when they are used in anodic or cathodic materials.

First claim

What is claimed is:

1 . A process for producing a battery separator, the process comprising gas assisted electrospinning a fluid stock to form a nanofiber mat, the fluid stock comprising (i) a plurality of ceramic or clay nanoparticles or a ceramic precursor, and (ii) a polymer, the separator comprising one or more nanofiber(s) comprising a continuous polymer matrix with ceramic or clay domains embedded therein, less than 50% of the embedded domains being aggregated.

2 . The process of claim 1 , further comprising annealing the nanofiber mat.

3 . The process of claim 1 , further comprising compressing the nanofiber mat.

4 . The process of claim 2 , further comprising compressing the nanofiber mat.

5 . The process of claim 2 , wherein the nanofiber mat is annealed at a temperature of less than 300° C.

6 . The process of claim 5 , wherein the nanofiber mat is annealed at a temperature of 100° C. to 200° C.

7 . The process of claim 2 , wherein the nanofiber mat is compressed at a pressure of 0.1 Mpa to 10 Mpa.

8 . The process of claim 1 , wherein the electrospinning is coaxially gas assisted.

9 . The process of claim 1 , wherein less than 25% of the embedded domains are aggregated.

10 . The process of claim 9 , wherein less than 10% of the embedded domains are aggregated.

11 . The process of claim 1 , wherein the polymer is selected from the group consisting of polyethylene (PE), ultra high molecular weight polyethylene (UHMWPE), polypropylene (PP), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), nylon, aramid, polyethylene terephthalate (PET), polyimide, polymethylmethacrylate (PMMA), and any combination thereof.

12 . The process of claim 1 , wherein the continuous polymer matrix comprises polyethylene (PE), ultra high molecular weight polyethylene (UHMWPE), polypropylene (PP), polyvinyl alcohol (PVA), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), nylon, aramid, polyethylene terephthalate (PET), polyimide, polymethylmethacrylate (PMMA), or any combination thereof.

13 . The process of claim 1 , wherein the ceramic is selected from the group consisting of silica, zirconia, alumina, and any combination thereof.

14 . The process of claim 1 , wherein the separator comprises 1-15 wt. % ceramic.

15 . The process of claim 14 , wherein the separator comprises 3-12 wt. % ceramic.

16 . The process of claim 1 , wherein the weight ratio of the ceramic nanoparticles or the ceramic precursor to polymer present in the fluid stock is at least 1:5.

17 . The process of claim 11 , wherein the polymer is selected from the group consisting of polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), and any combination thereof.

18 . The process of claim 12 , wherein the continuous polymer matrix comprises polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), or any combination thereof.

19 . A process for producing a battery separator, the process comprising gas assisted electrospinning a fluid stock to form a nanofiber mat, the fluid stock comprising (i) a plurality of ceramic or clay nanoparticles or a ceramic precursor, and (ii) a polymer, the separator comprising one or more nanofiber(s) comprising a continuous polymer matrix with non-aggregated ceramic or clay nanostructure(s) embedded therein, wherein the polymer matrix is PE, UHMWPE, PP, PVA, PAN, PEO, PVP, PVDF, PMMA, or a combination thereof, and wherein the one or more polymer nanocomposite nanofiber(s) comprises 0.5-50 wt. % ceramic and/or clay.

Assignees

• Univ Cornell

Inventors

• Joo Yong Lak
• Hansen Nathaniel S
• Cho Daehwan
• Kim Kyoung Woo

Classifications

• D01D5/0069

  characterised by the spinning section, e.g. capillary tube, protrusion or pin · CPC title

• D01F1/10

  Other agents for modifying properties · CPC title

• H01M4/0469

  Electroforming a self-supporting electrode; Electroforming of powdered electrode material · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title