`eo
`5,618,640
`[11] Patent Number:
`United States Patent 19
`Idota et al.
`[45] Date of Patent:
`Apr. 8, 1997
`
`
`CATTARIAA
`
`[54] NONAQUEOUS SECONDARY BATTERY
`
`[75]
`
`Inventors: Yoshio Idota; Masayuki Mishima;
`
`5,283,136
`5,284,721
`5,300,376
`
`2/1994 Peled et al.
`....sesescsesecenee 429/218 X
`2/1994 Beard...csssscesseeceseeceesseees 429/194
`
`4/1994 Plichta et al. cece 429/194 X
`
`Tsutomu Miyasaka,all of Kanagawa,
`Japan
`[73] Assignee: Pah}Photo Film Co., Ltd., Kanagawa,
`
`p
`
`0582173
`0615296
`
`[21] Appl. No.: 326,365
`
`[22]
`
`Filed:
`
`Oct. 20, 1994
`
`2/1994 European Pat. Off.
`.
`9/1994 European Pat. Off.
`.
`OTHER PUBLICATIONS
`Proceedings of the Symposium on High Power, Ambient
`Temperature Lithium Batteries, Phoenix, Arizona, Oct.
`13-17, 1991, vol. 92-15, pp. 101-112.
`.
`.
`Primary Examiner—Anthony Skapars
`Attorney, Agent, or Firm—Sughrue, Mion, Zinn, Macpeak &
`Foreign Application Priority Data
`[30]
`Seas
`Oct. 22, 1993
`[JP]
`Japan ssesssesssssctstenteeeeetees 5.264995
`ABSTRACT
`[57]
`Jan. 27, 1994
`[JP]
`Japan on...
`eeseseesessteceeenssenennes 6-007760
`
`Feb. 24, 1994=[JP] Japan veces esessessecesesseerese 6-026745
`
`Feb. 28, 1994
`[IP]
`Japan oo...
`esesstescsseseoteeeeterseeee 6-030206
`A nonaqueoussecondary battery comprising a positive elec-
`
`Mar. 11, 1994=[JP] Jaan veeeeccssecssseesesersneeserseeeee 6-066422 trode active material, a negative electrode active material,
`
`
`[SL]
`Int. CSsssansnnnnnnnnnincinnne HOM 614
`ane @ lithium sal’ Panne which the negative
`
`” contains(1)a compound capable o: electrode active material
`
`
`
`[52] US. CDs eeneere
`- 429/194, 429/218; 419/1
`intercalating and deintercalating lithium comprising an atom
`Field of Search ................:ayesteavecnecesecens 429/218, 194,
`[58]
`of the group TUB, IVB or VB ofthe periodic table, (2) an
`429/217, 252/182.1; 419/1, 26, 54
`amorphous compoundcontainingat least two atoms selected
`References Cited
`from the elements of the groups [JIB, IVB, and VB of the
`periodic table, (3) a compound capable of intercalating and
`U.S. PATENT DOCUMENTS
`deintercalating lithium containing at least one of the atoms
`.
`of the group IIIB, IVB, and VB of the periodic table and
`4,136,233
`1/1979 Eisenberg «0...teseseseeerees 429/218 X
`fluorine, or (4) a compound of the metal of the group IIB,
`iosose
`oioks wer a a
`“Sooam
`IVB or VBofthe periodic table, Zn, or Mg whichis capable
`
`
`4,751,158
`6/1988 Uchiyama et al. secu 429/218 X
`of intercalating and deintercalatinglithium. The nonaqueous
`4,808,498
`2/1989 Tarey et al. cassscseeeenteteneee 429/218
`Secondary battery of the invention exhibits improved charge
`
`4,808,499 .... 429/218_and discharge characteristics and improvedsafety.2/1989 Nagai et al. .....
`
`
`
`5,057,387
`10/1991 Masudaetal.
`429/218 X
`3/1993 [dota ....cececscceccesccseterstentsncerans 429/194
`5,196,278
`
`[56]
`
`9 Claims, 2 Drawing Sheets
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`hitithf
`oleerie)
`
`APPLE 1023
`
`APPLE 1023
`
`1
`
`
`
`U.S. Patent
`
`Apr. 8, 1997
`
`Sheet 1 of 2
`
`0002
`0009
`
`OO0S
`
`00°02
` I
`
`5,618,640
`
`
`
`OO0O0v
`~T
`O00
`
`TF
`
`HOG
`
`Se
`
`Sdo
`
`ltd
`
`2
`
`
`
`Wl
`
`NNNN
`
`me
`
`il
`
`NNNNNNANy
`
`:
`
`U.S. Patent
`
`
`
`2-22deeLL
`
`.
`wo,
`’
`.
`.
`:
`OEEEEEOSlA
`QSFoo a
`
`Apr. 8, 1997
`
`Sheet 2 of 2
`
`5,618,640
`
`FIG.3
`
`awe
`
`YhMeneeDocehetSielehemeeerDeaseeeonbee
`RkeeALLY
`
`aaeaeA
`
`NNNN
`
`it
`NNII
`ee:
`I
`
`,N
`
`Mi
`
`3
`
`
`
`5,618,640
`
`1
`
`NONAQUEOUS SECONDARY BATTERY
`
`FIELD OF THE INVENTION
`
`This invention relates to a nonaqueous secondary battery
`having improved charge and discharge cycle characteristics
`and improved safety.
`
`BACKGROUND OF THE INVENTION
`
`Negative electrode active materials for nonaqueous sec-
`ondary batteries typically include metallic lithium and
`lithium alloys. The problem associated with these active
`materials is that metallic lithium grows dendritically during
`charging and discharging to cause an internal short circuit,
`involving a danger of ignition becauseof high activity of the
`dendritical metal per se. To solve the problem, a calcined
`carbonaceous material capable ofintercalating and deinter-
`calating lithium has recently becn put
`to practical use.
`However, since the carbonaceous material has electrical
`conductivity by itself, metallic lithium is sometimes pre-
`cipitated on the carbonaceous material at the time of an
`overcharge or a rapid charge. It eventually follows that
`lithium grows dendritically thereon. This problem has been
`dealt with by altering a chargeror reducing the amountof the
`positive electrode active material to prevent an overcharge.
`Where the latter solution is adopted, however, the limited
`amount of the active material leads to a limited discharge
`capacity. Further, the carbonaceous material has a relatively
`low density and therefore a low capacity per unit volume.
`Thus, the discharge capacity is limited by both the amount
`of the active material and the capacity per unit volume.
`In addition to metallic lithium, lithium alloys and the
`above-mentioned carbonaceous material, negative electrode
`active materials so far proposed include TiS, and LiTiS,
`which are capable of intercalating and deintercalating
`lithium (U.S. Pat. No. 3,983,476); transition metal oxides
`having a rutile structure, such as WO,
`(U.S. Pat. No.
`4,198,476), spinel compounds, such as Li,Fe(Fe,)O, (JP-
`A-58-220362, the term “JP-A” as used herein means an
`“unexamined published Japanese patent application’); a
`electrochemically synthesized lithium compound of FeO,
`(U.S. Pat. No. 4,464,447); a lithium compound of Fe,03
`(JP-A-3-112070); Nb,O, (JP-B-62-59412 (the term “JP-B”
`as used herein means an “examined published Japanese
`patent application”) and JP-A-2-82447); FeO, Fe,O3,
`Fe,0,, CoO, Co,03, and Co,0, (JP-A-3-291862); amor-
`phous V0, (JP-A-4-223061); and transition metal oxides
`having their basic crystal structure changed by intercalation
`of a lithium ion (EP 567149). Any of these known com-
`pounds has a high oxidation-reduction potential, failing to
`provide a nonaqueous secondary battery having a discharge
`potential as high as 3 V and a high capacity.
`SnO, or Sn compoundsare used as an active material of
`lithium batteries as in Li, 93C0p9955Ng.94O. as a secondary
`battery positive electrode active material (EP 86-106301);
`SnO,-added V,O, as a secondary battery positive electrode
`active material
`(JP-A-2-158056); SnO,-added o-Fe,0;
`(preferred SnO, content: 0.5 to 10 mol %) as a secondary
`battery
`negative
`electrode
`active material
`(JP-A-62
`-219465); and SnO,as a primary battery positive electrode
`active material
`(Denki Kagaku oyobi Kogyo Butsuri
`Kagaku,Vol. 46, No. 7, p. 407 (1978)). With referenceto the
`use of SnO, or Sn compoundsas an electrochromic elec-
`trode, it is known that SnO, is capable of reversible inter-
`calation of an Li ion (see Journal of Electrochemical Soci-
`ety, Vol. 140, No. 5, L81 (1993) and that a film comprising
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`35
`
`60
`
`65
`
`2
`iInO, doped with 8 mol % of Sn (i.e., ITO) is capable of
`reversible intercalation of an Li ion (see Solid State lonic.,
`Vols. 28-30, p. 1733 (1988)). However, the electrode useful
`in an electrochromic system should be transparent,
`the
`active material is used in the form of a thin film formedby,
`for example, vacuum evaporation, and the electrode usually
`works at a considerably low current differing from the
`practical range of batteries. For example, Solid State Ionics,
`supra, shows a working current of 1 A to 30 A/cm? as an
`experimental example.
`Knownpositive electrode active materials include spinel
`compounds disclosed in JP-B-4-30146 and cobalt oxide
`disclosed in JP-B-63-59507.
`
`It is possible to combine these positive electrode active
`materials with an oxide mainly comprising Sn as a negative
`electrode active material to provide a nonaqueous secondary
`battery having a high discharge potential, a high capacity,
`improved charge and discharge cycle characteristics, and
`increased safety. Yet, the charge and discharge cycle char-
`acteristics are still unsatisfactory as described above, and it
`has been keenly demanded to further improve charge and
`discharge cycle characteristics.
`
`SUMMARYOF THE INVENTION
`
`An object of the present invention is to provide a non-
`aqueous secondary battery having improved charge and
`discharge cycle characteristics, a high discharge potential, a
`high discharge capacity, and increased safety.
`The above object of the present invention is accomplished
`by a nonaqueous secondary battery comprising a positive
`electrode active material, a negative electrode active mate-
`rial, and a lithium salt, in which (1) the negative electrode
`active material contains at least one compound capable of
`intercalating and deintercalating lithium mainly comprising
`an atom of the group 13, 14, or 15 (as referenced by the
`American Chemical Society format) of the periodic table,
`(2) the negative electrode active material mainly comprises
`an amorphous compound containing at
`least two atoms
`selected from the elements of the groups 13, 14, and 15 of
`the periodic tabic, (3) the negative clectrode active material
`is a compound capable ofintercalating and deintercalating
`lithium containing at least one of the atomsof the group 13,
`14, and 15 of the periodic table and fluorine, or (4) the
`negative electrode active material contains at
`least one
`compound of the atom of the group 13, 14, or 15 of the
`periodic table, Zn, or Mg which is capable of intercalating
`and deintercalating lithium.
`
`BRIEF DESCRIPTION OF THE DRAWING
`
`FIG. 1 is the X-ray diffraction pattern of compound D-1-A
`prepared in Synthesis Example D-1.
`FIG. 2 is a cross section of a coin battery prepared in
`Examples, wherein 1 indicates a negative electrode sealing
`plate, 2 indicates a negative electrode active material mix-
`ture pellet, 3 indicates a separator, 4 indicates a positive
`electrode active material mixture pellet, 5 indicates a col-
`lector, 6 indicates a positive electrode case, and 7 indicates
`a gasket.
`FIG. 3 is a cross section of a cylindrical battery prepared
`in Examples, wherein 8 indicates a positive electrode shcct,
`9 indicates a negative electrode sheet, 10 indicates a sepa-
`rator, 11 indicates a battery case, 12 indicates a battery cover,
`13 indicates a gasket, and 14 indicates a safety valve.
`
`4
`
`
`
`5,618,640
`
`3
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`The terminology “negative electrode active material pre-
`cursor’ as used herein is explained below. The inventors
`have found that SnO having an o-PbO structure, SnO,
`having a rutile structure, and the like do not act by them-
`selves as a negative electrode active material of a secondary
`battery but change their crystal structure on intercalation of
`lithium to act as a reversible negative electrode active
`material. That is, the charge and dischargeefficiency of the
`first cycle is as low as about 80% or 60%. Thus, the starting
`material, such as o&-PbO-structure SnO or rutile-structure
`SnO,, namely, a compound before lithium intercalation is
`called a “negative electrode active material precursor”.
`The negative electrode active material according to the
`present
`invention can be obtained by electrochemically
`intercalating a lithium ion into, for example, an oxide, an
`active material precursor. Lithium ion intercalation is con-
`ducted until the basic structure of the oxide is changed (for
`example, until
`the X-ray diffraction pattern changes) and
`also until the thus changed basic structure of the Li ion-
`containing oxide undergoes substantially no change during
`charging and discharging (for example, the X-ray diffraction
`pattern does not change substantially). The change in basic
`structure means change from a certain crystal structure to a
`different crystal structure or from a crystal structure to an
`amorphousstructure.
`Where the compoundrepresented by formulae (D to (V)
`of the present
`invention described in later is used as a
`negative electrode active material precursor, it was found
`that intercalation of lithium does not cause reduction of the
`respective metal (an alloy with lithium). This can be con-
`firmed from the fact that (1) observation under a transmis-
`sion electron microscopereveals no precipitation of a mctal
`(especially no precipitation of a dendrite), (2) the potential
`of lithium intercalation/deintercalation via a metalis differ-
`ent from that of the oxide, and (3) the lithium deintercalation
`loss with respect to lithium intercalation in SnO was about
`1 equivalent, which does not agree with a loss of 2 equiva-
`lents in the case where metallic tin is generated. Since the
`potential of an oxide is similar to that of a currently
`employed calcined carbonaceous compound,it is assumed
`that the bonding state of lithium is neither mere ionic
`bonding nor mere metallic bonding, similarly to a calcined
`carbonaceous compound. Accordingly,
`the negative elec-
`trode active material of the present invention is obviously
`different from conventional lithium alloys.
`It is preferable that the active material precursor which
`can be used in the present invention is substantially amor-
`phous at the time of battery assembly (before lithium ion
`intercalation). The term “substantially amorphous” as used
`herein means that an X-ray diffraction pattern using CuKa
`rays showsa broad scattering band with peaks between 20°
`and 40° in terms of 26 and may contain diffraction assigned
`to a crystalline structure.
`The maximum intensity of the peaks assigned to the
`crystalline structure appearing between 20=40° and 70° is
`preferably not higher than 500 times, still preferably not
`higher than 100 times, still more preferably not higher than
`5 times, the intensity of the peak of the broad scattering band
`appearing between 20=20° and 40°. It is the most preferred
`that the pattern exhibits no crystalline diffraction spectrum.
`Also, it is preferred that the active material precursor is
`substantially amorphousat the time of intercalating lithium
`ion.
`
`In the present invention, either the active material pre-
`cursor or the active material can be used as a negative
`
`10
`
`20
`
`25
`
`30
`
`40
`
`45
`
`50
`
`35
`
`60
`
`65
`
`in which they are
`
`4
`electrode. Hereinafter, cases are met
`represented as an active material.
`The metals of the groups 13 to 15 of the periodic table
`which can beused in the present invention include B, Al, Ga,
`In, TI, Si, Ge, Sn, Pb, P, As, Sb, and Bi, preferably B, Al, Si,
`Ge, Sn, Pb, P, As, Sb, and Bi, still preferably Al, Si, Ge, Sn,
`Pb, As, and Sb or B, Al, Si, Ge, Sn, and P.
`
`Examples of the negative electrode active material
`accordingto the presentinvention include GeO, GeO,, SnO,
`SiO, SnO,, PbO, PbO, Pb,O3, Pb,0,, Sb,03, Sb,O,,
`Sb,0., Bi,O3, Bi,0,, and Bi,O,, and non-stoichiometrical
`compounds of these oxides.
`Preferred of them are SnO, SnO., GeO, and GEO.,, with
`SnO and SnO,being particularly preferred. @-PbO-structure
`Sn0,rutile-structure 5nO,, GeO, and rutile-structure GeO,
`are preferred, with a-PbO-structure SnO andrutile-structure
`SnO, being particularly preferred.
`Still preferred negative electrode active materials are
`represented by formula (1):
`
`M'M?,M‘*,
`
`a
`
`wherein M’ and M?, which are different from each other,
`each representat least one of Si, Ge, Sn, Pb, P, B, Al, As, and
`Sb, preferably at least one of Si, Ge, Sn, Pb, P, B, Al, and Sb,
`still preferably at least one of Si, Ge, Sn, Pb, P, B, and Al;
`M* represents at least one of O, S, Se, and Te, preferably at
`least once of O and S, still preferably O; p represents a
`number exceeding 0 and not exceeding 10, generally from
`0.001 to 10, preferably from 0.01 to 5, still preferably from
`0.01 to 2; and q represents a number of from 1
`to 50,
`preferably 1 to 26, still preferably 1.02 to 6.
`Also, preferred are those of formula (D in which M? and
`M?are different from each other; M! representsat least one
`of Ge, Sn, Pb, Sb, and Bi; M? represents at least one atom
`of the groups 13, 14, and 15 of the periodic table (exclusive
`of Ge, Sn, Pb, Sb, and Bi when M? represents each of these);
`p represents a numberof from 0.001 to 1; and M* and q have
`the same meanings as defined in formula (I) above.
`The valency of M' or M? in formula (1) is not particularly
`limited and may be either a single valency or a mixed
`valency. The M* to M! ratio may vary continuously within
`arange of from more than 0 up to 10 molar equivalents. The
`amount of M‘, represented by q in formula (1), continuously
`varies accordingly.
`Of the compounds of formula (1), preferred are those in
`which M?is Sn,i.e., compounds represented by formula(II):
`
`SnM?,Mé,
`
`()
`
`wherein M?represents at least one of Si, Ge, Pb, P, B, Al, As,
`and Sb, preferably at least one of Si, Ge, Pb, P, B, Al, and
`Sb,still preferably at least one of Si, Ge, Pb, P, B, and Al;
`M®represents at least one of O and S, preferably O: p
`represents a number exceeding 0 and not exceeding 10,
`generally from 0.001 to 10, preferably from 0.01 to 5, more
`preferably a numberoffrom 0.01 to 1.5,still preferably from
`0.7 to 1.5; and q represents a number of from 1.0 to 50,
`preferably from 1.0 to 26, still preferably from 1.02 to 6.
`Still preferred of the compoundsrepresented by formula
`(ID are those represented by formula (II):
`
`SnM?,0,
`
`(Ip)
`
`wherein M? is as defined above, preferably Si; r represents
`a number of exceeding 0 and not exceeding 5.0, generally
`from 0.01 to 5.0, preferably a numberof from 0.01 to 1.5,
`
`5
`
`
`
`5
`still preferably from 0.7 to 1.5; and s represents a numberof
`SmSipgAlp.2Po20s,
`SnSip¢Alo3Po, 1029,
`from 1.0 to 26, preferably from 1.02 to 6.
`SnSipgAlo :Pp103;
`SnSip¢Aly:Po303.1,
`Examples of the compounds represented by formula (II)
`SmSipgAlo2Po,203.4,
`SmSipgAlg:Po203.25,
`or (Ii) are SnSig9:0; 92, SnGeg9)0; 92, SnPb9.919) o2:
`SnSip.4Alo.2Po.603.6:
`SnSig7Alp2Po303.45,
`SnPo.o19) 025: SNBo9191 915,
`SMAI9:01.015» SNSi9.¢102.02,
`SnSiAlyPy2035,
`SnSiAlpPy)403.5, SnSiAl,;Py 1,034,
`SnGey9;02.92, SnPb0.0192,025
`0.0102,025» S1Byg9192o155
`SnSip;Bo1Po993.6,
`SnSiAlyjP203 655
`SMSig5901.1, SNGep950, 1,
`Do.o5O1.15
`0.0501 25)
`SMSip.sBo.:P0.703.55 SnSipBosPo,1029, SnSip6BoaP,0.203,
`S1Bo9591075: SMSig.9502.1, SnGeg95021, SnPbo9s021;
`SnSiy¢By ;Po.303.1, SnSiggByP9103, SmSiggBp1 Po.303.55
`SnPy95021255
`0.0592,.975: SnSig,O;.2, SnGeg,O; >,
`SnSiBy:Po1034,
`SmSiBg2Po203.,
` SuSiBg1Po.203.¢5;
`SnPby10,2,
` SnP910i 35,
`S$nBy10115,
`SnSig O02»,
`SnSig, Pb: P9.503.565
`SMSip3PDp1P0,703.5,
`SnGeg10.2,
` SnPbp;022,
` SnPy10205, SB10215,
`SmSiggPbg3Po102.9,
`SnSigPhpPo203,
`SnSip,0,4,
` SnGey.,0,,,
`SnPby.O,4,
`SnPp20,5,
`SnSip«P091P9.303,1,
`SnSiggPbo:Po,103,
`SnBy2013,
` SnSig2024,
` SnGeg2024,
` SnPby20.4,
`SnSiggPbp1Po.303.5, SnSiPbg,Po103.,, SnSiPby2Pp.2O3, 2,
`SnPy2025,
`0.2923,
` SnSig301.6,
`SnGey30) ¢
`SnSiPbo:Pp.203.65>
`SnPAly 03.655
`SnPAlp303.95,
`SnPby30,.6,
`SnP930175,
` SnBy30, 45,
`SnSig;026,
`SnPogAlp103.15, SnPo.gAlo30245, SnPosAlo.1024, and
`SnGeg30.6,
`SnPbp3026,
`SnPo302.75, SB30245,
`SnP,;Alp02.7. The valency of Sn and M°®are not particu-
`SnS$ig7O54,
`SnGeg70,,,
`SnPby7O.,,
`SnPp70235,
`larly limited and maybeasingle valency or a mixed valency.
`SnBp70295,
`SmSip.g925,
`SnGep.025,
`SnPbp,025,
`The ratio of M° to Sn may vary continuously within a range
`SnPp,03, SnBygO,2, SuSiO3, SnGeO;, SnPbO,, SnPO; 5,
`of from 0 to 2 molar equivalents, and the amount of oxygen
`SnBO,5, SnSi;O34, SnGe,5034, SnPb, 203.4, SnP, .0,,
`continuously varies accordingly.
`SnB, 20,.g, SnSi,;0,, SnGe, ,0,, SnPb,;O,, SnP, 50,75,
`Additional examples of the compounds represented by
`SnB 503,25, SaSi,05, SnGezOs, s,pp205, SUPO,, SnB2O,,
`formulae (1) to (V) are shown below.
`SnSi,0,, SnGe,O,, SnPb,O,, SnP,O,, SnB,O., SnSiS,,
`SnSiy,Geg,O2.5,
`SnSig,Geg ;Pb9105.6,
`SnSiSe,, SnSiTe,, SnPS,;, SnPSe,;, SnPTe;5, SnBS,,,
` SnPbySig ;Or6,
`SnSip2Pb91026,
` SnGegrSig;Or¢,
`SnBSe,;,
` SnBTe,;,
` SnPo,03,
`SnBy,0O,5,
`and
`SnSiygGep,O3,
`SnGe,Pb,10%6,
`snpbo.2G€p 1926s
`Snip25BO3.
`SnSiggPby,O5,
`SnSiggGeo205,
`SnSiy;Gey503,
`The valency of Sn and M? in formula (ID) or (II) is not
`SnGeg9Sig103,
`SnSipgPbp.203,
`SnSigsPbg.503,
`particularly limited and may bea single valency or a mixed
`SnPbygSig.203>
`SnGegSip203,
`SnPbySig,03,
`valency. The ratio of M? to Sn in the compoundof formula
`SnPogGeg20s4,
`SnSiggGeo.,Pbp 1,03, SnPo9Gep 03.45,
`(I) may vary continuously within a range of from 0.01 to 10
` SnPogPbp203.4,
`SnPosGcp50325,
` SmPooPby103.45,
`molar cquivalents. Accordingly, the amount of M?, repre-
` SGeg.gPo2031,
`SmPosPbp.503.25,
` SnGep9P910395,
`sented by q in formula (ID, varies continuously. Similarly,
`SnPbo9Po.193.05:
`bo.370.203,1> SnPogGeg;Pbp1054,
`the ratio of M? to Sn in the compoundof formula (III) may
`SnBo9Gep;0255,
` SNBogGeg20,5,
`SnBgsGeo50275,
`vary continuously within a range of from 0.01 to 5.0 molar
`SnBo.9Pbp.10255,
` SnBo.gPbp202¢,
` SmBgsPg50275,
`equivalents. Accordingly, the amount of oxygen, represented
`SnGep9Bo,:02.95,
`SnGepgGo2029,
`by s in formula (III), varies continuously.
`SnPbp9By,192.958NPbpgBy2029,
` SnBogGep; Phy102.6,
`Of the compounds of formula (III), preferred are those
`SDSip.25Bo.2P9.203,
`SMSigsBy.2P9203,
`SnSig.9410.102.95>
`represented by formula (IV):
`SnSipsAlp9s02.75,
`SmSigsAlo10215, SnSipsAlp.50275,
`SnSi,Al,3025,
`SnSiAl,05.5,
`SnSigsBy9592.75,
`Snip5By,:9915,
`SMSipsBo50275,
`SNSip7Bg302455
`SnSig9Bo.1O2.95,
`SnSiByO33,
`SnSig5Pbg9502.75,
`SnSigs5Pby 0215,
`SnSigsPby50275,
`SnSig7Pby30245,
`SnSiggPbp 0295, SnSiPby033, SnSig ;Gey Pp903.65,
`SnSipGe1 Po.703.35,
`SNSig¢Gep4Po,103.255
`SnSip¢GegPp2031,
`SnSipGeoPo203 1,
`In formulac (IV) and (V), M®represents at least one of Ge,
`SnSiggGeo1 P910305;
`SnSipgGeg ;Po.303,55,
`B, Al, and Pb, preferably at least one of Ge, Al, and B, still
`SnSiGegyPo103.45, SmSiGeg»Pp2039, SnSiGeg,Pp2037,
`preferably Al; M’ represents at least one of Ge, B, and P;t
`SnSiggGegj Alp10295;
`SnSipgGeg ;Bo102.95,
`represents a number exceeding 0 and not exceeding 2.0
`SnSiggGep1 Sb103.95,
`SnSipgGeo Ing102.95,
`(preferably not exceeding 1.5), generally from 0.01 to 2.0,
`SMSipgGep;Pbp10395,
`SMSipBo Alp10>,
`preferably from 0.01 to 1.5; u represents a numberof from
`SnSiggSbp, A104g,
`SnPAly103,65)
`SPA],303.95,
`0.01 to 4.0, preferably from 0.01 to 3.5; v represents a
`SnPpgAlp 03.15,
`SnPpgAlo302.455
`SnPo5A] Oo.4,
`number exceeding O and not exceeding 2.0 (preferably not
`SmPp9sAlg30,7,
`PbSip919} 92,
`PbGe99191 02
`PbSig.9102.92; PbGeg9102.02, PbPo0191 025 PbOBo01> 91.0155
`exceeding 1.5), generally from 0.01 to 2.0, preferably from
`0.01 to 1.5; w represents a number exceeding 0 to not
`PbPp9102.025, PbGeg.9102.615, PbSig.9sO11, PbGeg9501.1,
`exceeding 2.0, generally from 0.01 to 2.0; and s represents
`PDSip0502.1» PbG2py95021, PbP9.9501.125: PbBo051.075:
`a numberof from 1.0 to 26, preferably from 1.02 to 10.
`0.05002.1257
` PbBo.9s02.075PbSip 022,
`PbGeg O22,
`Specific but non-limiting examples of the oxides repre-
`PbSig 0,2,
`PbGeg 0,5,
`PbP910225,
`PbBo10215;
`sented by formula ([V) or (V) are SnSigp5Bo.P9203,
`PbP9 Oj; 25,
`PbBgi:Oi15,
`PbSig2034,
`PbGeg20>,
`60
`
`SnSipsBo.2Po.203,—_SMSip9Po, 102.255 SnSipgPo.203.;,
`PDSig20,4,
` PbGep20,4,
`PbPy20,5,
`Bo202.3;
`SnSig7Py.302755
`SnSigsPo.sO3.255
`SnSig3Py.703 35,
`PbP920,5,
`PbBg20,3,
`PbSig30.,6,
`PbGeg302,,
`SMSig2P9,g03.4
`SnSigsP9.102.25,
`SuSip Geo:P3 65;
`PbSip30,6,
`PbGeg30,,,
`PbP930275,
`PbBy30245,
`SmSigGeo :Po.70335,
`SnSiggGeg4Po103.25,
`PbPy301 75,
`PbBo30; a5;
`PDSig2Gep;O>¢,
`SnSip6Geg2P0.2051;
`SnSipGeyjPo2931,
`PbGEp919,192.6;
`PbP92Gep1057,
`PbGep2Po102655
`SMSiggGepPo103.95,
`SMSipgGeg; Pp303555
`PbByGe,O25,
`PbGep2By10255,
`PbSip7054,
`PbGeg.702.4,
`PbP7O275,
` PbBg7O205,
` PbSipgO.5,
`SnSiGeyg;Po1P3.45, SnSiGeg>Po2P3., SnSiGepPoP37,
`SnSig jAlo.1P9995.55
`SnSig3Alp:Po.703.s,
`PbGey.gOr4, PbPyg03, PbBy,O,5, PbSiO;, PbGeO,,
`
`Of the compounds of formula (IV), preferred are those
`represented by formula (V):
`
`SnSi,P,M°,O,
`
`SnSi,P,,Al,M’,,0,
`
`5,618,640
`
`6
`
`20
`
`25
`
`30
`
`(IV)
`
`40
`
`(V)
`
`45
`
`350
`
`55
`
`65
`
`6
`
`
`
`5,618,640
`
`10
`
`20
`
`30
`
`35
`
`8
`7
`PbSiygGeg203,
`PbSiggGeg ,O3,
`PbBO.s.
`PbPO,,,
`pyrophosphate, tin phosphite, stannous sulfate, stannic sul-
`fate.
`PbPogGey205.45
`PbSiysGey505,
`PbPy Gey103 455
`Thesilicon compoundsinclude SiO,, SiO, organic silicon
`PbBggGe29>65
`PbP9sGey.503.25,
` PDBg5Geg10265,
`halide compounds such as silicon tetrachloride, silicon,
`PbGepSig203,
`PbBysGeysO>75,
`PbGeQoSig,105,
`tetrafluoride, trichloromethylsilane, dimethyldichlorosilane
`
`PbGeygP9193.05,—PbGeggPo.2031, PbGeyBy 0295,
`and tetraethhylsilane, alkoxysilance compounds such as
`PbGepgBy2029,
`PbSi;5O,,
`PbGe,5O,, PbP,;0,-5,
`tetramethoxysilane and tetraethoxysilane, and hydroxysi-
`PbB, <0355, PbGe,0,;, PbSi,0,, PbGe,O,, PbP,O,,
`lane compoundssuch as trichlorohydroxysilane.
`PbB2O5,
`GeSig.o1O1.02, GeSiggiO202, GeSigsOj 4,
`The germanium compoundsinclude GeO, GeO, germa-
`GeSiggsO21, GeSig;O,2, GeSig,O22,
`GeSip20,4,
`nium tetrachloride, and alkoxy germanium compounds such
`GeSig,0,,4,
` GeSip30,,,
` GeSipz0O..6,
`GeSip;O,
`as germanium tetramethoxide and germanium tetraethoxide.
`GeSiy503, GeSi,,0,4, GeSig,0,4,, GeSiO,, GeSiO,,
`The lead compounds include PbO, pyo, pp203, Pb3O0,,
`GeSi, 50,, GeSi, 505, GeP9191.025,
`GePo.o192025,
`PbCl,,
`lead chlorate,
`lead perchlorate,
`lead nitrate,
`lead
`GePo9591125: GePo9502125: GePp10125, GePo10225,
`carbonate, lead formate, lead acetate, lead tetraacetate, lead
`GePo2015,
` GePo2025,
` GePo30175;
`€Pp 30275;
`tartrate, lead diethoxide, lead ditisopropoxide).
`GePy50225,
`GePo503.25,
`GePo7O275, GePo70375,
`The phosphorus compound includes phosphorus pentox-
`GePOQ, ;,
`GePO,5,
`GeP, 50475»
`GeP, 50575,
`ide, phosphorus oxychloride, phosphorous pentachloride,
`GeBoo191 15:
`GeBo0192015
`€Bo 9591 075)
`phosphorustrichloride, phosphorous tribromide, trimethyl
`GeBo502.075, GeBy19115, GeBy10215, GeBy20,5,
`phosphate, triethyl phosphate, tripropy] phosphate, stannous
`GeBy2023, GeBg39, 45,
`GeBg30245,
`GeBy50; 75,
`pyrophosphate, and boron phosphate.
`GeBo,.50275, GeBy702.95, GeBy703,05, GeBO,;, GeBO; 5,
`The boron compound includes boron sesquioxide, boron
`trichloride, boron tribromide, boron carbide, boric acid,
`GeB, ;O35 and GeB, <0,25.
`The use of anyof the compoundsrepresented by formulae
`trimethyl borate, triethyl borate,
`tripropyl borate, tributyl
`(D to (V) as a main negative electrode active material affords
`borate, boron phosphide, and boron phosphate.
`a nonaqueous secondary battery having excellent charge and
`The aluminum compound includes aluminum oxide
`(o-alumina or B-alumina), aluminum silicate, aluminum
`discharge cycle characteristics, a high discharge potential, a
`triisopropoxide, aluminum tellurite, aluminum chloride, alu-
`high capacity and high safety.
`The pronouncedly excellent effects of the present inven-
`minum boride, aluminum phosphide, aluminum phosphate,
`aluminum lactate, aluminum borate, aluminum sulfide, and
`tion come from the use of a compound containing Sn in
`aluminum sulfate.
`which Sn is present with divalency. The valency of Sn can
`be determined through chemical
`titration,
`for example,
`The antimony compoundincludes antimony tribromide,
`according to the method described in Physics and Chemistry
`antimonytrichloride, diantimony trioxide, and triphenylan-
`timony.
`of Glasses, Vol. 8, No. 4, p. 165 (1967). It is also decided
`from the Knight shift in the solid nuclear magnetic reso-
`Calcination is carried out preferably at a rate of tempera-
`nance spectrum of Sn. For example, in broad-line NMR
`ture rise of 4° to 2000° C./min,still preferably 6° to 2000°
`measurement, metallic Sn (zero valent Sn) showsa peak in
`C./min, most preferably 10° to 2000° C./min; at a calcina-
`an extremely low magnetic field in the vicinity of 7000 ppm
`tion temperature of 250° to 1500° C.., still preferably 350° to
`with reference to Sn(CH3),, whereas the peak of SnO
`1500° C., most preferably 500° to 1500° C.; for a period of
`(divalent Sn) appears around 100 ppm, and that of SnO,
`0.01 to 100 hours, still preferably 0.5 to 70 hours, most
`(tetravalent Sn) appears around —600 ppm. Likethis, the
`preferably 1
`to 20 hours. After calcination, the system is
`cooledat a rate of temperature drop of2° to 107° C/min,still
`Knight shift largely depends on the valency of Sn, the center
`preferably 4° to 107° C./min,still more preferably 6° to 107°
`metal, with the ligands being the same. The valency can thus
`be determined by the peak position obtained by ''°Sn-NMR
`C./min, most preferably 10° to 10’° C./min.
`analysis.
`The term “rate of temperature rise” as used herein means
`The negative electrode active matcrial of the present
`an average rate of temperature rise from 50% calcination
`invention may contain various compounds, such as com-
`temperature (° C.) up to 80% calcination temperature (° C.),
`poundsofthe group 1 elements (e.g., Li, Na, K, Rb, and Cs),
`and the term “rate of temperature drop” as used herein
`transition metals (e.g., Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn,
`mecans an average rate of temperature drop from 80%
`YY, Zr, Nb, Mo, Te, Ru, Rh, Pd, Ag, lanthanoid metals, Hf, Ta,
`calcination temperature (° C.) to 50% calcination tempera-
`ture (° C.).
`W, Re, Os, Ir, Pi, Au, Hg), the group 2 elements (e.g., Be,
`Mg,Ca,Sr, Ba), and the group 17 elements(e.g., F, Cl, Br,
`Cooling of the calcined product may be effected either
`1). Further, it may also contain dopants of various com-
`within a calcining furnace or out of the furnace, for example,
`pounds (e.g., compounds of Sb,
`In, Nb) for improving
`by pouring the product into water. Super-quenching methods
`electrical conductivity. The addition amountthereofis pref-
`described in Ceramics Processing, p. 217, Gihodo (1987),
`erably 0 to 20 mol %.
`such as a gun method, a Hammer-Anvil method, a slap
`The compoundsof formulae (I) to (V) can be synthesized
`method, a gas atomizing method, a plasma spray method, a
`by either a calcination method or a solution method.
`centrifugal quenching method, and a melt drag method, can
`For instance,
`the calcination method is conducted by
`also be used. Further, cooling may be conducted bya single
`roller method or a twin-roller method described in New
`calcining a mixed compound of M’ compound and M?
`compound (where M! and M?, which are different from each
`Glass Handbook, p. 172, Maruzen (1991). Where the mate-
`other, each represent Si, Ge, Sn, Pb, P, B, Al, As, Sb).
`rial melts during calcination, the calcined product may be
`The tin compounds include SnO, SnO,, Sn,03, Sn,0,,
`withdrawn continuously while feeing the raw materials. The
`$n,0,3.H,O, Sn,0,,;, stannous hydroxide, stannic oxyhy-
`molten liquid is preferably stirred during calcination.
`droxidc, stannic acid, stannous oxalate, stannous phosphate,
`The calcining atmosphere preferably has an oxygen con-
`orthostannic acid, metastannic acid, parastannic acid, stan-
`tent of not more than 100% by volume, preferably not more
`nous fluoride, stannic fluoride, stannous chloride, stannic
`than 20% by volume, more preferably not more than 5% by
`chloride,
`stannous bromide,
`stannic bromide,
`stannous
`volume. An inert gas atmosphere isstill preferred. Inert gas
`iodide, stannic iodide, tin selenide, tin telluride, stannous
`includes nitrogen, argon, helium, krypton, and xenon.
`
`60
`
`45
`
`50
`
`55
`
`65
`
`7
`
`
`
`5,618,640
`
`9
`The compound of formulae (I) to (V) preferably has an
`average particle size of from 0.1 to 60 um. The calcined
`product can be ground to size by means of well-known
`grinding machinesorclassifiers, such as a mortar, a ball mill,
`a sand mill, a vibration bal] mill, a satellite ball mill, a
`planetary ball mill, a spinningair flow type jet mill, and a
`sieve. If necessary, wet grinding using water or an organic
`solvent, such as methanol, may be conducted. The grinds are
`preferably classified to obtain a desired particle size either
`by dry or wet classification by mcans of a sieve, an air
`classifier, etc.
`According to one of the embodiments of the present
`invention in which the negative electrode active material is
`an oxide containing fluorine,
`the fluorine in the negative
`electrode active material
`strengthens the structure and
`chemical stability of a compound oxide. In particular, fluo-
`rine in an amorphous oxideis effective to further enhance
`the amorphous properties thereby improving the electro-
`chemical structural stability.
`Specific examples of the fluorine-containing negative
`electrode active material or
`a precursor
`thereof are
`GeFy0p9,
`GeFy20) 9,
`SNF2099;
`SnFp201.9,
`SnSiFp,0.g,
`PbFy,O; 2;
`PbFo20) 9,
`P 29.2029,
`Pb3Fy4033,
`SbFy20,y,
`Sb2Fy203g,
`wy204.9
`BizFy4033, BigFy403.2, and Bi,Fy.O,4, and non-stoichio-
`metrical compounds or compound oxidesthereof.
`Preferred of these fluorine-containing negative electrode
`active materials are fluorine-containing SnO, SnO, , GeO,
`GeO,, and SnSiO,, with fluorine-containing SnSiO, being
`still preferred. Fluorine-containing and amorphous SnO,
`SnO, , GeO, GeO,, and SnSiO, are particularly preferred.
`A preferred fluorine content in the fluorine-containing
`negative electrode active material is from 10 to 100 mol %,
`particularly 20 to 50 mol %, based onthe total amountof the
`metal elements in the active material.
`The F-containing neg