Composite material, negative electrode, and sodium secondary battery

Patent metadata

Field	Value
Publication number	US-2016156035-A1
Application number	US-201414584595-A
Country	US
Kind code	A1
Filing date	Dec 29, 2014
Priority date	Nov 27, 2014
Publication date	Jun 2, 2016
Grant date	—

Abstract

Disclosed is a composite material, having the chemical structure represented below: Na 1+(4−a)x Ti 2−x M x (PO 4 ) 3 /C, wherein the M is an element with valence a, a is a positive integer from 1 to 4, and 0.1≦x≦0.4. The composite material can be mixed with an electrically conductive agent and a binder to form a negative electrode for application in a sodium secondary battery.

First claim

What is claimed is:

1 . A composite material, having the chemical formula:
Na 1+(4−a)x Ti 2−x M x (PO 4 ) 3 /C, wherein M is an element with valence a, a is a positive integer from 1 to 4, and 0.1≦x≦0.4.

2 . The composite material as claimed in claim 1 , wherein the sodium titanium metal phosphate has a Na + superionic conductor structure.

3 . The composite material as claimed in claim 1 , wherein the sodium titanium metal phosphate content is 90 wt % to 97 wt %, and the carbon material content is 10 wt % to 3 wt %.

4 . The composite material as claimed in claim 1 , wherein M comprises magnesium, aluminum, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, or a combination thereof.

5 . A negative electrode, comprising:
a conductive layer on an electrically conductive substrate, wherein the electrically conductive layer includes:
1 part by weight of the composite material as claimed in claim 1 ;
0.055 to 0.33 parts by weight of a binder, and
0.055 to 0.33 parts by weight of an electrically conductive agent.

6 . The negative electrode as claimed in claim 5 , wherein the electrically conductive agent comprises carbon black, graphite, carbon nanotube, carbon nano fiber, or a combination thereof.

7 . The negative electrode as claimed in claim 5 , wherein the binder comprises poly(tetrafluoroethylene), poly(vinylidene fluoride), polyvinyl alcohol, carboxymethylcellulose, styrene-butadiene rubber, or a combination thereof.

8 . The negative electrode as claimed in claim 5 , wherein the electrically conductive substrate comprises metal foil, metal mesh, metal foam, or a combination thereof of stainless steel, aluminum, copper, or nickel.

9 . A sodium secondary battery, comprising:
the negative electrode as claimed in claim 5 ; a positive electrode; a separator film disposed between the positive electrode and the negative electrode; and an electrolyte disposed between the positive electrode and the negative electrode.

10 . The sodium secondary battery as claimed in claim 9 , wherein the positive electrode comprises sodium metal oxide (Na x MO 2 , M=Fe, Mn, Co, Ni, or a combination thereof, and 0<x≦1), sodium-rich metal hexacyanoferrate (Na 2 M x Fe(CN) 6 , M=Fe, Co, Ni, Cu, Zn, Mn, or a combination thereof, and 0<x≦1), sodium metal phosphate (Na 3 M 2 (PO 4 ) 3 , M=Al or V), or a combination thereof.

11 . The sodium secondary battery as claimed in claim 9 , wherein the separator comprises glass fiber film, filter paper, polypropylene film, polyethylene film, or a combination thereof.

12 . The sodium secondary battery as claimed in claim 9 , wherein the electrolyte comprises an organic type electrolyte or an aqueous type electrolyte.

13 . The sodium secondary battery as claimed in claim 12 , wherein the aqueous type electrolyte comprises Na 2 SO 4 , NaCl, NaNO 3 , or a combination thereof.

Assignees

• Ind Tech Res Inst

Inventors

• Hung Tai-Feng
• Yeh Yu-Wen
• Chang Wen-Sheng
• Yang Chang-Chung

Classifications

• H01M4/364

  as mixtures · CPC title

• H01M4/5825 Primary

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/58

  of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates · CPC title

• H01M2004/027

  Negative electrodes · CPC title