UNITED STATES DEPARTMENT OF COMMERCE
`United States Patent and Trademark Office
`
`November 25, 2014
`
`TIDS IS TO CERTIFY THAT ANNEXED IS A TRUE COPY FROM THE
`RECORDS OF THIS OFFICE OF THE FILE WRAPPER AND CONTENTS
`OF:
`
`APPLICATION NUMBER: 091989,844
`FILING DATE: November 21, 2001
`PATENT NUMBER: 6,680,143
`ISSUE DATE: January 20, 2004
`
`By Authority of the
`Under Secretary of Commerce for Intellectual Property
`, and Director of the United zte~rademark Office
`
`VIAHOLLEY ~
`
`Certifying Officer
`
`SONY EXHIBIT 1003
`
`Page 1 of 364
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`·Certificate
`JUL 0 6 2004
`Lit~ium metal oxide electrodes for lithium cells and batteries
`of C:orrection
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`UNITED STATES PATENT AND TRADEMARK OrncE
`
`Page 1 of 1
`
`COMMISSIONER FOR PATENTS
`UNITED STATES PATENT AND TRADEMARK OFFICE
`WASHINGlON, D.C. 20231
`www.uspto.gov
`
`CONFIRMATION NO. 2526
`
`CLASS
`429
`
`GROUP ART UNIT
`1745
`
`ATTORNEY
`DOCKET NO.
`
`1111~11 IIIII 111111111111111 111111 1111 111111 1111 IIIII IIIII 111111 II 1111
`Bib Data Sheet
`
`SERIAL NUMBER
`09/989,844
`
`FILING DATE
`11/21/2001
`RULE
`
`!APPLICANTS
`Michael M. Thackeray, Naperville, IL;
`Christopher S. Johnson, Naperville, IL;
`Khalil Amine, Downers Grove, IL;
`Jaekook Kim, Naperville, IL;
`
`I** CONTINUING DATA*************************
`
`J
`THIS APPLICATION IS A CIP OF 09/887,842 06/21/2001 D- '
`\J\(-{._ c
`
`WHICH CLAIMS BENEFIT OF 60/213,618 06/22/2000
`
`V
`
`I"* FOREIG~PLICATIOr ;7****************
`!'
`I
`IF REQUIRED, FOREIGN FILING LICENSE GRANTED** SMALL ENTITY **
`** 03/01/2002
`'
`Dyes~
`Foreign Priority claimed
`35 USC 119 (a-d) conditions D yes
`. no D ' t after
`met
`Allowancr (, "'
`~erified and
`~cknowledged
`~DDRESS
`Emrich & Dithmar
`Suite 3000
`300 South Wacker Drive
`Chicago ,IL 60606
`
`Examiner's Signatur~
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`Initials
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`SHEETS
`STATE OR
`COUNTRY DRAWING
`IL
`14
`
`TOTAL
`CLAIMS
`26
`
`INDEPENDENT
`CLAIMS
`7
`
`trJTLE
`
`Lithium metal oxide electrodes for lithium cells and batteries
`
`FILING FEE FEES: Authority has been given in Paper
`to charge/credit DEPOSIT ACCOUNT
`RECEIVED No.
`for following:
`No.
`657
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`ID All Fees
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`ID 1.16 Fees (Filing)
`D 1.17 Fees ( Processing Ext. of
`time)
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`I
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`I
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`ID Other
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`ID credit
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`\
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`PATENT APPLICATION SERIAL NO. 0 9- Cf gC( 9 4 L{ ,
`
`U.S. DEPARTMENT OF COMMERCE
`PATENT AND TRADEMARK OFFICE
`FEE RECORD· SHEET
`
`11/2b/2001 MAHMEDl 00000033 09989844
`370.00 OP
`lb8.00 OP
`54.00 OP
`
`01 FC:201
`02 FC:202
`03 FC:203
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`PT0-1556
`(5/87)
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`'U.S. GPO: 2000468-987/39595
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`ANL-JN-00-063A
`IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`
`Applicants
`
`Michael M. Thackeray, et at.
`
`Title
`
`Date
`
`LITHIUM METAL OXIDE ELECTRODES FOR
`LITHIUM CELLS AND BATTERIES
`
`November 21, 2001
`
`Asst. Commissioner of Patents
`BOX CPA
`Washington, D.C. 20231
`
`REQUEST FOR CONTINUATION-IN-PART PATENT APPLICATION
`
`Sir:
`
`Under the provisions of 37 CFR §1.53(b), please institute a continuation-in-part
`
`application of the following prior application.
`
`Applicants: Michael M. Thackeray, Christopher S. Johnson and Khalil Amine
`
`Title
`
`LITHIUM METAL OXIDE ELECTRODES FOR
`LITHIUM CELLS AND BATTERIES
`
`Parent Serial No.: 09/887,842
`
`Parent Filing Date: June 22, 2000
`
`This continuation-in-part application contains claims 1-26.
`
`The filing fee is calculated as follows:
`
`CERTTFICA TE OF MAILING BY EXPRESS MAIL
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`Express Mail Label Number...!;E~Ls~s~ss~os~32:!:8~Us~--...,--­
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`United States Postal Service "Express Mail Post Office to
`Addressee" service under 37 C.F.R. 1.10 on the date indicated
`below, before the last scheduled pick-up, and is addressed to the
`U.S. Patent and Trademark Office, P .0. Box 2327 BOX NEW
`~~}A£ftd~ril£g{l· Arlington, VA. 22202
`
`Page 5 of 364
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`Page 5 of 364
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`

`
`Basic fee
`
`26 total claims (6 extra)
`
`7 independent claims (4 extra)
`
`Total
`
`$370.00
`
`54.00
`
`168.00
`
`$ 592.00
`
`A check in the amount of $592.00 is enclosed.
`
`A Declaration, Power of Attorney and Verified Statement Claiming Small Entity
`
`Status (37 CFR 1.90(f) and 1.27(d) is being filed under separate cover.
`
`An Assignment of the invention is being filed under separate cover.
`
`Please charge any additional fees or credit any overpayment incident to the
`
`filing of this continuation-in-part application under 37 CFR 1.53(b) to Deposit Account
`
`No. 05-1060. A duplicate copy of this paper is enclosed.
`
`Respectfully submitted,
`
`Emrich & Dithmar
`Attorneys for Applicants' Assignee
`Suite 3000
`300 South Wacker Drive
`Chicago, Illinois 60606
`Telephone: 312-663-9800
`
`Dated: __ l-it (_z"+t f-=o....._\ __ _
`
`Page 6 of 364
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`))-~~-0\
`
`ANL-IN-00-063A
`IN THE UNITED STATES PATENT ANO TRADEMARK OFFICE
`
`Applicants
`
`Michael M. Thackeray, et al.
`
`Title
`
`Date
`
`LITHIUM METAL OXIDE ELECTRODES FOR
`LITHIUM CELLS AND BATIERIES
`
`November 21, 2001
`
`Asst. Commissioner of Patents
`BOX CPA
`Washington, D.C. 20231
`
`REQUEST FOR CONTINUATION-IN-PART PATENT APPLICATION
`
`Sir:
`
`Under the provisions of 37 CFR §1.53(b), please institute a continuation-in-part
`
`application of the following prior application.
`
`Applicants: Michael M. Thackeray, Christopher S. Johnson and Khalil Amine
`
`Title
`
`LITHIUM METAL OXIDE ELECTRODES FOR
`LITHIUM CELLS AND BA TIERIES
`
`Parent Serial No.: 09/887,842
`
`Parent Filing Date: June 22, 2000
`
`This continuation-in-part application contains claims 1-26.
`
`The filing fee is calculated as follows:
`
`CERTIFICATE OF MAILING BY EXPRESS MAIL
`
`Express Mail Label Number_!=E~L8~5~88~08~3~28~U~S -:------:---
`1 certify that this correspondence is being deposited with the
`United States Postal Service "Express Mail Post Office to
`Addressee" service under 37 C.P.R. 1.10 on the date indicated
`below, before the last scheduled pick-up, and is addressed to the
`U.S. Patent and Trademark Office, P.O. Box 2327 BOX NEW
`~~~ Aff1-'8Sr1i£~· Arlington, VA. 22202
`
`Page 7 of 364
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`Page 7 of 364
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`Page 7 of 364
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`

`
`Basic fee
`
`26 total claims (6 extra)
`
`7 independent claims (4 extra)
`
`Total
`
`$370.00
`
`54.00
`
`168.00
`
`$ 592.00
`
`A check in the amount of $592.00 is enclosed.
`
`A Declaration, Power of Attorney and Verified Statement Claiming Small Entity
`
`Status (37 CFR 1.90(f) and 1.27(d) is being filed under separate cover.
`
`An Assignment of the invention is being filed under separate cover.
`
`Please charge any additional fees or credit any overpayment incident to the
`
`filing of this continuation-in-part application under 37 CFR 1.53(b) to Deposit Account
`
`No. 05-1060. A duplicate copy of this paper is enclosed.
`
`Respectfully submitted,
`
`Emrich & Dithmar
`Attorneys for Applicants' Assignee
`Suite 3000
`300 South Wacker Drive
`Chicago, Illinois 60606
`Telephone: 312-663-9800
`
`Dated: __ I-tt {=z>+, f-=-o..._\ __ _
`
`Page 8 of 364
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`ANL-IN-00-063A
`
`APPLICATION FOR U.S. LETTER PATENT
`
`Title:
`
`LITHIUM METAL OXIDE ELECTRODES FOR
`LITHIUM CELLS AND BATTERIES
`
`lnventor(s): Michael M. Thackeray, Christopher S. Johnson, Khalil Amine and
`Jaekook Kim
`
`CERTIFICATE OF MAILING BY EXPRESS MAIL
`
`Express Mail Label Number_"'E""L8,_,57'-8':'80'-':8""32""87'U"'-S --:--:--:-:--:---::-:--::--:--::-(cid:173)
`I certifY that this correspondence is being deposited with the United States
`Postal Service "Express Mail Post Office to Addressee" service under 3 7
`C.F.R. 1.10 on the date indicated below, before the last scheduled pick-up,
`and is addressed to the U.S. Patent and Trademark Office, P.O. Box 2327
`BOX NEW PATENT APPLICATION, Arlington, VA. 22202
`E:nily Ridyard
`
`JO."(cid:173)
`(Signature)
`Novernber 21, .2001
`(Date of Deposit)
`
`Page 9 of 364
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`•
`
`•
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`CONTRACTUAL ORIGIN OF THE INVENTION
`
`The United States Government has rights in this invention pursuant to Contract
`
`No. W-31-109-ENG-38 between the U.S. Department of Energy (DOE) and The
`
`University of Chicago representing Argonne National Laboratory.
`
`RELATED APPLICATIONS
`
`This continuation-in-part application of U.S. Pat. App. Serial No. 09/887,842 filed
`
`June 21, 2001 which claimed priority under 35 U.S.C. § 1.78(a)(3) of provisional
`
`application Serial No. 60/213,618 filed June 22, 2000.
`
`BACKGROUND OF THE INVENTION
`
`This invention relates to lithium metal oxide positive electrodes for non-aqueous
`
`lithium cells and batteries~ Morespecifically, it relates to lithium-metal-oxide electrode
`
`compositions and structures, having in their initial state in an electrochemical cell, a
`
`general formula xliM02•(1-x)Li2M'03 alternatively Li2_xMxM' 1-x03_x in which O<x<1 and
`..
`where M is one or more ion with an average oxidation state of three and with at least
`
`one ion being Mn, and where M' is one or more ions with an average oxidation state of
`
`four selected preferably from Mn, Ti and Zr; or, where M is one or more ion with an
`
`average oxidation state of three and with at least one ion being Ni, and where M' is one
`
`or more ions with an average oxidation state of four with at least one ion being Mn. In
`
`one embodiment of the invention, the Mn content should be as high as possible, such
`
`0
`\0
`~
`~
`;4j
`
`00 + SO'!
`
`"'F
`Iii
`~
`
`~ ru
`~
`0 10
`~
`
`Page 10 of 364
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`

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`2
`
`that the LiM02 component is essentially LiMn02 modified in accordance with this
`
`invention. In a second embodiment of the invention, the Ni content should be as high
`
`as possible such that the LiM02 component is essentially LiNi02 modified in accordance
`
`with this invention. In a further embodiment of the invention, the transition metal ions
`
`and lithium ions may be partially replaced by minor concentrations of one or more
`
`mono- or multivalent cations such asH+ derived from the electrolyte by ion-exchange
`
`with u+ ions, and/or Mg2+ and Al3+ to impart improved structural stability or electronic
`
`conductivity to the electrode during electrochemical cycling.
`
`Prior application serial no.09/887/842 filed June 21, 2001 taught one or more
`
`=
`·-;-- 10 cations M or M' in a lithium metal oxide cathode, such as LiM02 or Li2M'03 where M
`
`has an oxidation state or valence of three and M' has an oxidation state or valence of
`
`four. Although one of ordinary skill in the art would have clearly understood that the
`
`11
`
`~ !F w
`
`valences or oxidation states taught included ions which averaged oxidation state of
`
`three or average oxidation states of four, this continuation-in part application explictily
`
`states what was understood from the earlier filed '842 application and adds newly
`
`obtained data.
`
`SUMMARY OF THE INVENTION
`
`Lithium-metal oxide compounds of general formula LiM02, where M is a trivalent
`
`transition metal cation such as Co, Ni, Mn, Ti, V, Fully executed, with a trivalent oxidation
`
`20 state and with electrochemically inactive substituents such as AI are very well known and
`
`are of interest as positive electrodes for rechargeable lithium batteries. The best-known
`
`electrode material is LiCo02 , which has a layered-type structure and is relatively expensive
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`3
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`compared to the isostructural nickel and manganese-based compounds. Efforts are
`
`therefore being made to develop less costly electrodes, for example, by partially
`
`substituting the cobalt ions within LiCo02 by nickel, such as in LiNi0_8Co0_20 2 or by
`
`exploiting the manganese-based system LiMn02 • Such layered compounds are
`
`sometimes stabilized by partially replacing the transition metal cations within the layers by
`
`other metal cations, either alone or in combination. For example, u+ and/or Mg2+ ions may
`
`be introduced into the structure to improve the electronic conductivity of the electrode, or
`
`Al 3+ and/or Ti4+ ions to improve the structural stability of the electrode at high levels of
`
`delithiation. Examples of such compounds are LiNi 0_8Co0_15AI 0_050 2 and
`
`'. !~··=--ru
`
`A major problem of layered LiM02 compounds containing either Co or Ni (or both)
`
`is that the transition metal cations, M, with a trivalent oxidation state are oxidized during
`
`charge of the cells to a metastable tetravalent oxidation state. Such compounds are highly
`
`oxidizing materials and can react with the electrolyte or release oxygen. These electrode
`
`materials can, therefore, suffer from structural instability in charged cells when, for
`
`example, more than 50% of the lithium is extracted from their structures; they require
`
`stabilization to combat such chemical degradation.
`
`Although the layered manganese compound LiMn02 has been successfully
`
`synthesized in the laboratory, it has been found that delithiation of the structure and
`
`2 o subsequent cycling of the LixMn02 electrode in electrochemical cells causes a transition
`
`from the layered Mn02 configuration to the configuration of a spinel-type [Mn 2]04 structure.
`
`This transformation changes the voltage profile of the Li/LixMn02 cell such that it delivers
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`0.
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`I
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`I
`\
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`4
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`capacity over both a 4V and a 3V plateau; cycling over the 3V plateau is not fully
`
`reversible which leads to capacity fade of the cell over long-term cycling. Other types of
`
`LiMn02 structures exist, such as the orthorhombic-form, designated O-LiMn02 in which
`
`sheets of Mn06 octahedra are staggered in zig-zig fashion unlike their arrangement in
`
`layered LiMn02 . However, O-LiMn02 behaves in a similar way to layered LiMn02 in lithium
`
`cells; it also converts to a spinel-like structure on electrochemical cycling.
`
`Therefore, further improvements must be made to LiM02 electrodes, particularly
`
`LiMn0 2 and LiNi0 2, to impart greater structural stability to these electrode materials during
`
`electrochemical cycling in lithium cells and batteries. This invention addresses the stability
`
`·f 10
`
`T
`
`of LiM02 electrode structures, particularly those in which M is Mn and Ni, and makes use
`
`of a Li2M'03 component in which M' is one or more ions with an average oxidation state
`
`i~
`
`of four to improve their stability.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The invention consists of certain novel features and a combination of parts
`
`hereinafter fully described, illustrated in the accompanying drawings, and particularly
`
`pointed out in the appended claims, it being understood that various changes in the details
`
`may be made without departing from the spirit, or sacrificing any of the advantages of the
`
`present invention.
`
`20
`
`FIGURE 1 depicts a schematic representation of a Li 2M'03-M02-LiM02 phase
`
`diagram, in which M (in the LiM02 component) is one or more ions with an average
`
`oxidation state of three, and in which M' (in the Li2M'03 component) is one or more ions
`
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`(''.,
`
`with an average oxidation state of four;
`
`5
`
`FIGURE 2 depicts the X-ray diffraction pattern of a xli2Mn03•(1-x)LiNi0_8Co0_20 2
`
`electrode composition;
`
`FIGURE 3 depicts the X-ray diffraction pattern of a xli2Mn1_x Tix03•(1-x)LiNi0_8Co0.20 2
`
`electrode composition;
`
`FIGURE 4 depicts the X-ray diffraction pattern of a xli2Ti03•(1-x)LiMn02 electrode
`
`composition;
`
`FIGURE 5 depicts the X-ray diffraction pattern of a Li 1_2Ni0.4Mn0.402 electrode
`
`component composition;
`
`FIGURE 6 depicts the X-ray diffraction pattern of a Li 1_9Mn0_9Ni0_20 3 electrode
`
`component composition;
`
`FIGURE 7 depicts the electrochemical profile of a Li/xli2Mn03•(1-x)LiNi0_8Co0_20 2
`
`electrochemical cell;
`
`FIGURE 8 depicts the electrochemical profile of a Li/xli2Ti03•(1-x)LiMn02
`
`electrochemical cell;
`
`FIGURE 9 depicts the X-ray diffraction pattern of a xli 2Ti03•(1-x)LiNi0_5Mn0_50 2
`
`electrode composition;
`
`FIGURE 10 depicts the cyclic voltammogram of a xli2Ti03•(1-x)LiNi0_5Mn 0_50 2
`
`electrode;
`
`20
`
`FIGURE 11 depicts
`
`the electrochemical charge/discharge profiles of a
`
`Li/xli2 Ti03•(1-x)LiNi0_5Mn0_50 2 electrochemical cell;
`
`FIGURE 12 depicts the capacity versus cycle number plot of a Li/xli2Ti03•(1-
`
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`(-·",
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`I
`
`I
`
`6
`
`x)LiNi 0_5Mn 0_50 2 electrochemical cell;
`
`FIGURE 13 depicts a schematic representation of an electrochemical cell; and
`
`FIGURE 14 depicts a schematic representation of a battery consisting of a plurality
`
`of cells connected electrically in series and in parallel.
`
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`0 '·
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`!
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`7
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`DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
`
`This invention relates to stabilized LiM02 electrodes whereby an electrochemically
`
`inert rocksalt phase Li2M03 is introduced as a component to the overall electrode structure
`
`as defined, in its initial state, by the general formula xliM02•(1-x)Li2M'03 alternatively Li2_
`
`xMxM' 1-x0a-x in which O<x<1, preferably 0.8~x<1, and more preferably 0.9~x<1, and where
`
`M is one or more ion with an average oxidation state of three and having at least one ion
`
`selected from Mn and where M' is one or more ions with an average oxidation state of four
`
`selected preferably from Mn, Ti and Zr , or alternatively, where M is one or more ion with
`
`~
`
`an average oxidation state of three and having at least one ion selected from Ni and where
`
`~~ 10 M' is one or preferably more ions with an average oxidation state of four having at least
`-;~
`
`one ion selected from Mn. These compounds can be visualized as lying on the UM02 -
`
`Li2M'03 tie-line of the Li2M'03-M02-LiM02 phase diagram shown schematically in Fig. 1.
`
`From a consideration of charge balance, because lithium and oxygen ions are
`
`monovalent (+1) and divalent (-2), respectively, it necessitates that when the M cations
`
`are of one type such as in LiMn02, LiCo02 and LiNi02, the oxidation state of theM cations
`
`must be trivalent. However, it stands to reason that when two or more M cations reside
`
`in the LiM02 structure, the oxidation state of the M cations may either be all trivalent, or
`
`they may be of mixed valence such that the average oxidation state of the M cations
`
`overall is three or trivalent. Examples of the latter case would, in principle, be 1)
`
`20 Li(Mn 0.5Ni0.5)0 2 if the oxidation state of the Mn ions is tetravalent and the oxidation state
`
`of the Ni ions is divalent, as is the case for the lithium-manganese-nickel-oxide spinel
`
`Li[Mn1.5Ni0.5]04 ; 2) Li(Mn0.4Ni0.4AI0.2)02 if the oxidation state of the Mn ions is four or
`
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`tetravalent, the oxidation state of the Ni ions is divalent, and the oxidation state of the AI
`
`ions is trivalent; 3) Li(Mn0.4Ni0_4Li0_2)02 , if the Mn ions are tetravalent, the Ni ions are
`
`trivalent and the Li ions are monovalent; and 4) Li(Mn0_5Ni0_4Li0_1)02 if the Mn ions are
`
`tetravalent, the Li ions are monovalent, and if 0.1 Ni ions are trivalent and 0.3 Ni ions are
`
`divalent.
`
`=
`c 3
`·=
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`~
`·~ 10
`>=
`7'
`E
`~
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`~
`0
`~~
`
`The rocksalt phase Li2Mn03 has a layered-type structure in which discrete layers of
`
`lithium ions alternate with layers containing Mn and Li ions (in a 2:1 ratio) between the
`
`close-packed oxygen sheets. Note that, in this respect, the formula Li2Mn03 can be written
`
`in layered notation as Li(Mn 213Li 113)02, in which the Li and Mn within round brackets
`
`represent the ions in one layer. A difference between Li2Mn03 and the layered LiM02
`
`compounds is that the Mn ions in Li2Mn03 are tetravalent and cannot be easily
`
`electrochemically oxidized by lithium extraction, whereas in the LiM02 compounds the
`
`transition metal cations Mare trivalent and can be electrochemically oxidized. Because
`
`Li2Mn03 has a rocksalt phase, there is no energetically favorable interstitial space for
`
`additional lithium; therefore, Li2Mn03 cannot operate as an insertion electrode and cannot
`
`be electrochemically reduced. The xliM02•(1-x)Li2M'03 structure may be either a solid
`
`solution of the two components or a domain structure with a common oxygen array for both
`
`the LiM02 and Li2Mn03 components, but in which the cation distribution can vary such that
`
`domains of the two components exist side by side. Such a solid solution or domain
`
`20 structure does not rule out the possibility of cation mixing and structural disorder,
`
`particularly at domain or grain boundaries. In a generalized xliM02•(1-x)Li2M'03 Iayered
`
`structure, one layer contains M, M' and Li ions between sheets of close-packed oxygen
`
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`9
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`ions, whereas the alternate layers are occupied essentially by lithium ions alone. By
`
`analogy, in a xliM02•(1-x)Li2M'03 structure that contains monoclinic LiMn02 as the LiM02
`
`component, it is believed that the tetravalent M' ions can partially occupy theM positions
`
`in the monoclinic layered LiMn02 structure, thereby providing increased stability to the
`
`overall structure.
`
`In a further embodiment of the invention, from the foregoing arguments, it stands
`
`to reason that the lithium and the tetravalent M' ions in the Li2M'03 component of the
`
`xLiM02•(1-x)Li2M'03 structure can be partially replaced by other monovalent or tetravalent
`
`~
`
`cations. Of particular significance to the invention is the replacement of Mn in an Li2Mn20 3
`
`-~ 10
`. ..E
`·:-
`
`component by Ti or Zr which are known to form isostructural compounds Li2 Ti03 and
`
`Li2Zr03, respectively; such components are expected to enhance the structural stability
`
`f:;J
`of the xliM0 2•(1-x)Li2M'03 electrode. Furthermore, it stands to reason that the lithium and
`~d: w M' ions in the Li2M'03 component of the xliM0 2•(1-x)Li2M'03 structure can be partially
`
`H' F
`
`replaced by other monovalent, or multivalent ions, such that the substitution maintains
`
`charge neutrality, thereby introducing electrochemical activity to the Li2M'03 component
`
`and giving it LiM02-type characteristics; in principle, examples of such components are 1)
`
`Li1.8Mn0_9Ni0 _30 3 , written alternatively in LiM02 form as Li (Mn 0_6Ni0_2Li0_2) 0 2 , in which the
`
`lithium ions are monovalent, the manganese ions are tetravalent, and the nickel ions are
`
`divalent which can be electrochemically oxidized to the tetravalent state in a lithium cell;
`
`20 and 2) Li 1_9Mn 0_9Ni0_20 3, written alternatively in LiM02 form as Li (Mn 0_60Ni 0_13Li0_27) 0 2 , in
`
`which the lithium ions are monovalent, the manganese ions are tetravalent, and the nickel
`
`ions are 50% divalent and 50% trivalent, all of which can be electrochemically oxidized to
`
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`(
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`10
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`the tetravalent state in a lithium cell.
`
`In the electrodes of the present invention, theM and M' ions can be disordered in
`
`the electrode structure. It is preferable that the Mn content should be as high as possible,
`
`such that the LiM02 component is essentially LiMn02.
`
`In a further embodiment of the
`
`invention, the Ni content should be as high as possible such that the LiM02 component is
`
`essentially LiNi02 modified in accordance with the invention. In yet a further embodiment
`
`of the invention, the transition metal ions and lithium ions may be partially replaced by
`
`minor concentrations (typically less than 10 atom percent) of other mono- or multivalent
`
`cations such as u+, Mg2+ or Al 3+ to impart improved structural stability or electronic
`
`-F 10 conductivity to the electrode during electrochemical cycling. In addition, the xliM02·(1-
`
`x)Li2M'03 structures of the invention may include H+ ions, for example, resulting from the
`
`removal acidic H+ species from the electrolyte by ion-exchange with u+ ions. It stands to
`
`a :.
`iF
`
`iW. ·-
`
`reason, therefore, that the present invention includes the introduction of mono- or divalent
`
`cations into the structure, and that the electrodes of the invention may therefore depart
`
`slightly from the ideal stoichiometry as defined by the formula xliM02•(1-x)Li2M'03•
`
`It has been shown in the past that Li2Mn03 (and isostructural Li2Mn 1_xZrx0 3) which
`
`is electrochemically inactive, can be used as a precursor material to form an
`
`electrochemically active charged xMn0 2•(1-x)Li2Mn03 electrode structure in which x is
`
`approximately equal to 0.91; this value of x translates to a composition of the layered
`
`20 structure Li1.1Mn 0.90 2 • These charged xMn0 2•(1-x)Li 2Mn03 compounds have been
`
`prepared by leaching Li20 from the Li2Mn03 (Li20·Mn02) structure with acid such as
`
`sulphuric acid (U.S. patent no. 5, 153,081). However, the acid treatment causes a shear
`
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`11
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`of the oxygen array, such that the resulting xMn02•(1-x)li2Mn03 structures are no longer
`
`close-packed but have an oxygen arrangement that provides octahedral and trigonal
`
`prismatic sites in alternate layers. During relithiation, for example with Lil in acetonitrile,
`
`it has been demonstrated that the oxygen sheets shear back to close-packing and that the
`
`phase transformation yields a xliMn02•(1-x)Li2Mn03-type structure. However, such phase
`
`transformations are undesirable in rechargeable battery systems, because they can
`
`adversely affect the efficiency and rechargeability of the electrode. Thus, a major
`
`advantage of this invention is that this phase transformation can be avoided by starting
`
`directly with a discharged xliMn0 2•(1-x)li2Mn03 electrode in the cell because the non-
`;iJ w 10 aqueous removal of lithium does not appear to cause the phase transition to yield the
`
`~
`
`structure (non close-packed) generated by acid leaching of Li2Mn03•
`
`Furthermore, it is important to note that even though the relithiation of a xMn02•(1-
`
`x)li2Mn03 electrode of the prior art in an electrochemical cell yields the same formulation
`
`~
`
`as the electrodes of the present invention, i.e., xliMn02•(1-x)li2Mn03, the applicants
`
`believe that the structures of the electrode materials of the present invention are
`
`significantly differentfrom those ofthe prior art and will be unequivocally distinguished from
`
`one another by high-resolution transmission electron microscopy, i.e., differences will be
`
`evident in the microstructural features of the xliMn02•(1-x)Li2Mn03 electrodes of the
`
`present invention and those of the prior art. For example, because the lithiated
`
`20 xliMn02•(1-x)li2Mn03 electrode structures of the prior art are derived from a non-close-
`
`packed xMn02•(1-x)li2Mn03 structure, which is obtained by the acid leaching of, and Li20
`
`removal from, a li2Mn03 precursor as described above, the microstructures of the prior art
`
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`12
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`electrode materials will be characterized by high concentrations of defects and stacking
`
`faults, as is evident by the broad peaks in their X-ray diffraction patterns, in contrast to the
`
`electrode materials of the present invention that are more crystalline and ordered as
`
`reflected by the relatively sharp and well-resolved peaks in their X-ray diffraction patterns
`
`(Figs. 2, 3 and 4).
`
`Another disadvantage of the acid-treated compounds of the prior art ('081 patent)
`
`xMn02•(1-x)Li2Mn03, is that they represent charged positive electrodes, whereas lithium-
`
`ion batteries require positive electrodes in the discharged state, for example, LiM0 2
`
`=
`~
`
`electrodes (M=Co, Ni, Mn). Moreover, the charged xMn02•(1-x)Li2Mn03 electrodes of the
`+: 10 prior art require dehydration before use so that they can be used effectively in lithium cells.
`
`By contrast, the xliMn02•(1-x)Li2Mn03 electrodes of this invention are prepared in the
`
`discharged state and are essentially anhydrous materials and are more stable to heat-
`
`treatment and long-term storage in air compared to the xMn02•(1-x)Li2Mn03 materials of
`
`the prior art, which are known to transform on storage to a gamma-Mn02-type structure as
`
`reported by Johnson et al in J. Power Sources 81-82, 491 (1999).
`
`In one embodiment, this invention extends to include xliM02•(1-x)Li2M'03
`
`electrodes stabilized by isostructural rocksalt Li2M'03 compounds other than M'= Mn, Ti,
`
`Zr as described in the preceding sections. Examples of such compounds are Li2Ru03,
`
`Li 2Re03, Li 21r03, and Li 2Pt03 which may contribute a portion of the electrochemical
`
`20 capacity of the electrode.
`
`One of the difficulties that has been encountered in synthesizing xliM02•(1-
`
`x)Li2M'03 electrodes, in which M is Mn, has been to keep the valency of the manganese
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`( .
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`I
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`13
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`ions equal, or close to its trivalent state. This has been successfully accomplished by the
`
`inventors with a hydrothermal method or process under basic conditions using LiOH and/or
`
`KOH. This invention, therefore, extends to include a hydrothermal process or method for
`
`synthesizing xliM0 2•(1-x)Li2M'03 compounds in which M is one or more trivalent ion with
`
`at least one ion being Mn, and in which M'is a tetravalent ion. Such methods of synthesis
`
`are undertaken in a pressurized autoclave, preferably between 5 and 35 atmospheres and
`
`at temperatures ranging between 100 and 250°C and most preferably at 10-20 atm and
`
`temperatures between 180 and 230°C for about 6 to 12 hours or more if necessary. For
`
`example, 0.15LiMn02•85Li2 Ti03 electrodes have been successfully prepared by this
`
`process from precursor materials consisting of manganese oxide (Mn 20 3},
`
`lithium
`
`hydroxide (LiOH•H 20) and titanium isopropoxide (Ti[OCH(CH 3) 2] 4 )
`
`in a potassium
`
`hydroxide (KOH) solution at 220°C and at 15 atmospheres pressure.
`
`It has been recently demonstrated that layered lithium-chromium-manganese-oxide
`
`and lithium-cobalt-manganese-oxide electrodes of general formula xliCr02•(1-x}Li2Mn03
`
`and xliCo02•( 1-x}Li2Mn03 provide electrochemical stability when cycled between 4.5 and
`
`2.0 V in electrochemical lithium cells.
`In particular, a Li(Cr0_4Mn0.4Li0.2)02 electrode
`(alternatively, 0.4LiCr02•0.4Li2Mn03) delivers approximately 150 mAh/g at 25 oc and 200
`mAh/g at 55 oc at an average cell voltage of 3.5 V vs. Li. However, because the Li2Mn03
`
`!;"""""::
`
`lbJ
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`=~ ¥.J
`i::i:3
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`F
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`=
`
`F...::.. ' ~
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`0
`6
`'
`
`component is electrochemically inactive, the electrochemical capacity derived from the cell
`
`2o
`
`is due to the oxidation of cr+ to cr>+ during the electrochemical charging of the cells. This
`
`system has an immediate disadvantage because it is known that the high oxidation states
`
`of chromium such as those found in Cr30 8 are dangerous and are a major health hazard
`
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`(
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`....-·~
`)
`
`14
`
`whereas the electrodes of the present invention operate predominantly off a M3+/M4+
`
`couple, notably a Mn3+/4+ couple. For the cobalt compound, xliCo02•(1-x)Li2Mn03 , no
`
`significant advantage is gained in overcoming the cost limitations of the electrode because
`
`the cobalt ions, not the manganese ions, provide all the electrochemical capacity of the
`
`electrode.
`
`The following examples of stabilized xliMn02•(1-x)Li2Mn03 electrodes and LiM02
`
`and Li2M'03 components containing either manganese and/or nickel describe the principles
`
`~
`
`of the invention as contemplated by the inventors, but they are not to be construed as
`
`limiting examples.
`
`10
`
`EXAMPLE 1
`
`The electrode material 0.2Li2Mn03•0.8LiNi0.8Co0.20 2
`
`that can be written,
`
`alternatively, as Li(Ni0.58Mn0.18Co0.15Li0.09)02 was prepared by the reaction of Ni(N03h,
`
`Co(N03h, Mn02 , and LiOH in the required stoichiometric amounts at 800°C in air or
`
`oxygen for about 16 hours. The powder X-ray diffraction pattern of this compound
`
`indicates an essentially single-phase product with a layered-type structure (Fig. 2).
`
`EXAMPLE 2
`
`be written, alternatively, as Li(Ni0.58Mn0.09Ti0.09Co0.15Li0.09)02 was prepared by the reaction
`
`of Ni(N03) 2, Co(N03h, Mn02, Ti02 (anatase) and LiOH in the required stoichiometric
`
`amounts at 800°C in air or oxygen for about 16 hours. The powder X-ray diffraction pattern
`
`of this compound indicates an essentially single-phase product with a layered-type
`
`Page 23 of 364
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`

`
`15
`
`structure (Fig. 3).
`
`EXAMPLE 3
`
`The electrode material 0.15Li2 Ti03•0.85LiMn02 that can be written, alternatively, as
`
`Li(Ti0_14Mn0_79Li0_d02 was prepared by the hydrothermal reaction of Mn20 3 , Ti02 (anatase)
`
`and LiOH in the required stoichiometric amounts at 220°C and 15 atmospheres pressure
`
`for about 10 hours. The powder X-ray diffraction pattern of this compound indicates an
`
`essentially single-phase product with a layered-type structure (Fig. 4).
`
`EXAMPLE 4
`
`The e