A storage device having excellent cycle lifetime, an electrode used in this storage device, and a production method of the electrode are provided. An electrode comprising an active material and a conductive carbon including oxidized carbon. A surface of the active material is covered by the conductive carbon. A Raman spectrum of the active material covered by the conductive carbon includes a peak intensity (a) derived from the active material and a peak intensity (b) of D-band derived from the conductive carbon. A peak intensity ratio (b)/(a) between the peak intensity (a) and the peak intensity (b) is 0.25 or more.

A doped phosphorus-sulfur iodide solid electrolyte, a preparation method therefor, and use thereof. The chemical formula of said solid electrolyte is Li.sub.6-xM.sub.xP.sub.1-xS.sub.5I, in which 0<x<0.8, and M is tungsten and/or molybdenum. Said method comprises: 1) mixing a lithium source, a phosphorus source, an iodine source, a sulfur source, and an M source in an inert atmosphere, and then ball-milling same to obtain a solid electrolyte precursor; and 2) sintering the solid electrolyte precursor obtained in step 1) in an inert atmosphere or in vacuum to obtain the doped phosphorus-sulfur iodide solid electrolyte.

Provided are a cobalt-free positive electrode material for a lithium ion battery, a preparation method therefor and a lithium ion battery. The method for preparing the cobalt-free positive electrode material for the lithium ion battery comprises: mixing lithium nickel manganese oxide with sulfate, so as to obtain a first mixture; and reacting the first mixture at a predetermined temperature, so as to obtain the cobalt-free positive electrode material. The cobalt-free positive electrode material comprises lithium nickel manganese oxide and a cladding layer of an outer surface thereof, and the cladding layer comprises lithium sulphate. The lithium ion battery comprises the cobalt-free positive electrode material. The cobalt-free positive electrode material has a relatively high electrical performance and a relatively low alkali content.

Provided are a cobalt-free positive electrode material for a lithium ion battery, a preparation method therefor and a lithium ion battery. The method for preparing the cobalt-free positive electrode material for the lithium ion battery comprises: mixing lithium nickel manganese oxide with sulfate, so as to obtain a first mixture; and reacting the first mixture at a predetermined temperature, so as to obtain the cobalt-free positive electrode material. The cobalt-free positive electrode material comprises lithium nickel manganese oxide and a cladding layer of an outer surface thereof, and the cladding layer comprises lithium sulphate. The lithium ion battery comprises the cobalt-free positive electrode material. The cobalt-free positive electrode material has a relatively high electrical performance and a relatively low alkali content.

The present invention provides a binder for a secondary battery that can reduce the initial resistance value of the secondary battery. A binder for a secondary battery comprising a polymer compound, wherein the polymer compound contains repeating units represented by formulae (1), (2), and (3):

##STR00001## in formula (1), R.sup.1 is a hydrogen atom or a methyl group, and M is a hydrogen atom or an alkali metal atom; and in formula (3), R.sup.2 is a hydrogen atom or a methyl group; and when a total ratio of repeating units constituting the polymer compound is taken as 100 mol %, a total ratio of the repeating unit represented by formula (3) is less than 2 mol %.

The present invention provides a binder for a secondary battery that can reduce the initial resistance value of the secondary battery. A binder for a secondary battery comprising a polymer compound, wherein the polymer compound contains repeating units represented by formulae (1), (2), and (3):

##STR00001## in formula (1), R.sup.1 is a hydrogen atom or a methyl group, and M is a hydrogen atom or an alkali metal atom; and in formula (3), R.sup.2 is a hydrogen atom or a methyl group; and when a total ratio of repeating units constituting the polymer compound is taken as 100 mol %, a total ratio of the repeating unit represented by formula (3) is less than 2 mol %.

A secondary battery with excellent cycle performance is provided. The secondary battery is an all-solid-state battery including a positive electrode current collector layer, a base film, a positive electrode active material layer, a buffer layer, and a solid electrolyte layer. The base film contains titanium nitride. The positive electrode active material layer contains lithium cobalt oxide. The buffer layer contains titanium oxide. The solid electrolyte layer contains a titanium compound. By using titanium oxide for the buffer layer, a side reaction between the positive electrode active material layer and the solid electrolyte layer can be suppressed, and cycle performance can be improved.

A lithium ion battery according to the present invention comprises a positive electrode, a negative electrode, a positive electrode lead that is connected to the positive electrode, an insulation tape that covers the positive electrode lead, and an electrolyte solution. The insulation tape comprises a base material layer that is mainly composed of an organic material, and a filler layer that is provided on the base material layer; the filler layer contains an oxide compound of an alkaline earth metal; and the electrolyte solution contains fluorine.

A novel polyfluorene-based ionomer, an anion exchange membrane, a method for preparing the polyfluorene-based ionomer, and a method for fabricating the anion exchange membrane are proposed. The polyfluorene-based ionomer contains no aryl ether bonds in the polymer backbone and includes piperidinium groups incorporated into the repeating units. The anion exchange membrane is fabricated from the polyfluorene-based ionomer. The anion exchange membrane has good thermal and chemical stability, excellent mechanical properties, and high ion conductivity. Due to these advantages, the anion exchange membrane can be applied as a membrane for an alkaline fuel cell and to a binder for an alkaline fuel cell or water electrolysis.

A secondary battery with favorable cycle performance is provided. Alternatively, a secondary battery with higher capacity is provided. A positive electrode active material layer including a first graphene layer, a second graphene layer, and a positive electrode active material. The first graphene layer includes a first region covering the positive electrode active material. The second graphene layer includes a second region covering the positive electrode active material and a third region overlapping with the first region. The first region includes a plane positioned between the positive electrode active material and the third region and formed of arranged six-membered carbon rings. The positive electrode active material includes a fourth region with a layered rock-salt structure. A lithium layer with a layered rock-salt structure included in the fourth region is substantially perpendicular to the plane formed of six-membered carbon rings and included in the second region.