CA2022191C - Carbonaceous material and a non-aqueous electrolyte cell using the same - Google Patents
Carbonaceous material and a non-aqueous electrolyte cell using the same Download PDFInfo
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- CA2022191C CA2022191C CA002022191A CA2022191A CA2022191C CA 2022191 C CA2022191 C CA 2022191C CA 002022191 A CA002022191 A CA 002022191A CA 2022191 A CA2022191 A CA 2022191A CA 2022191 C CA2022191 C CA 2022191C
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- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10C—WORKING-UP PITCH, ASPHALT, BITUMEN, TAR; PYROLIGNEOUS ACID
- C10C3/00—Working-up pitch, asphalt, bitumen
- C10C3/02—Working-up pitch, asphalt, bitumen by chemical means reaction
- C10C3/04—Working-up pitch, asphalt, bitumen by chemical means reaction by blowing or oxidising, e.g. air, ozone
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
- C04B35/528—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite obtained from carbonaceous particles with or without other non-organic components
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/04—Processes of manufacture in general
- H01M4/0438—Processes of manufacture in general by electrochemical processing
- H01M4/0459—Electrochemical doping, intercalation, occlusion or alloying
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids 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
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/027—Negative electrodes
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0025—Organic electrolyte
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
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- Organic Chemistry (AREA)
- Ceramic Engineering (AREA)
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Abstract
A carbonaceous material and a non-aqueous electrolyte cell using the carbonaceous material as an anode are disclosed. The carbonaceous material has an interlayer spacing, d oo2, of not less than 3.70 angstroms and a true density of less than 1.70 g/cm3, and contains from 0.2 to 5.0 weight % of phosphorus. The carbonaceous material has a large doping capacity for Li, and the non-aqueous electrolyte cell using the material has a large capacity and improved charge-discharge cycle characteristics.
Description
~o~~~o~
BACKGROUND OF TIIE INVENTION
This invention relates to a carbonaceous material capable of doping and de-doping lithium and a method for producing the same and also to a non-aqueous electrolytic cell having the carbonaceous material as a negative electrode.
A recent trend toward the miniaturization of electronic instruments requires a high energy density of cell. To satisfy such a requirement, a variety of secondary cells have been proposed. In such a cell, there is a non-aqueous electrolyte cell using lithium, which has been extensively studied for practical utility.
I-Iowever, for the practical applications of the non-aqueous electrolyte cell, the following disadvantages are involved in the use of lithium metal as a negative electrode.
(1) Charging takes a time as long as 5 - 10 hours with poor quick charging properties.
BACKGROUND OF TIIE INVENTION
This invention relates to a carbonaceous material capable of doping and de-doping lithium and a method for producing the same and also to a non-aqueous electrolytic cell having the carbonaceous material as a negative electrode.
A recent trend toward the miniaturization of electronic instruments requires a high energy density of cell. To satisfy such a requirement, a variety of secondary cells have been proposed. In such a cell, there is a non-aqueous electrolyte cell using lithium, which has been extensively studied for practical utility.
I-Iowever, for the practical applications of the non-aqueous electrolyte cell, the following disadvantages are involved in the use of lithium metal as a negative electrode.
(1) Charging takes a time as long as 5 - 10 hours with poor quick charging properties.
(2) Short cycle life.
It is accepted that these are all ascribed to the lithium rnetal, resulting from the change in shape of the lithium negative electrode, the formation of dendrite and the inactivation of lithium accompanied by the repetition of charging and discharging.
One measure for solving the above problem, there has been proposed the use of a negative electrode wherein lithium is not used as a single material but :Ls doped with a carbonaceous material. This makes use of easy electrochemical formation of rx carbon layer. compound of lithium. ror instance, when a carbonaceous rnateri.al used as a negative electrode is charged :Ln non-aqueous electrolyte solution, lithiurn in the positive electrode :Ls electrochemically doped in the :Lnterlayers of tLre negative carbon. 'fh<s :L a.thiurn-Japed c;arban acts as rr 1:l.thiurn electrode and the l:Lth:lum 1s de-doped from the carbon interlayers upon discharge, returning Lo tire positive electrode.
'fhe electric capacity per unit we:Lglrt a.f.' tyre carbonaceaus materia:L is determ:Lned depending on the amount of doped l:Lthiurn. In order to increase the charge and discharge capacivty, it :Ls des:Lrab:Le to .Lrrcrrase tlrc anraunt of doped I,LtIr.Lurn as :Large, rm pass l.b_Lc;. ('1'Irn tlnoorc3l;.l.crrJ.
ulrlaer lim:l.t ie a rate of one 1_..L acorn per 6 crtrbon atoms. ) II.Ltherto, the carbonaceous rnater:l.al used as the negat:Lve elecLrad a of this type of ce:l:L includes <;arbanaceaus mater lals abi;a.Lned :('ram organ:lc materia:Ls as is known, for examp:Le, i'rom Japanese Laid-open 1'aterrt Application No. 62-122066 or No. 62-90863.
Ilowever, the amount of doped lithium a.n the hittrerto known carbonaceous rnaterlals Ls not; so high that it i_s only 2~~~~~
approximately half the theoretical.
OBJECTS AND SUMMARY IF 1'lIE INVENTION
It; is arz object of the present invention Lo provide a carbonaceous materl.a:L hav:Lng a large doping capac:Lty 'for Li .
I1; l.s another object of the present :Lnvent:lon t;o provide an improved non-aducous e:Lect;rolyt;e cel:L hav:i.ng large capacity and improved charge-discharge cycle charac;ter:l.si.c;s.
Occ;orcl:lng Lo one, aspect oi' the pr-rsent; lnverrtion, there is provided a carbonaceous material having an :Lnterlayer spac:lng, doo2, of not less tharr 3.70 angstroms and a true density of less than 1.70 g/crn' , having no exotlrerm:lc peak at not :Less than 700°C as measured by a dt.Crractaou thermal analys.l.s l.n air st;retzrn, and containing from 0.2 to 5.0 weight % of phosphorus.
According Yo tznot;her aslyect; of I;he prr,sc;nt; Lrrvcnt;.f.orr, there .Ls a.l.go prov.i.ded tz uorr--tzclur,«riv a l.r,<;l;ro.lytc cc; l.:l.
wlr lc;lr comprises till fzllUde Ot' a c;arborrac;eorrs muter ltz:1 hav.l.rrg tzn an a.nter:Layer spac.tng, doom, of not less thtzn 3.70 angstrorns tzncl tz true dens.i. t;y of :Less t;trtzn 1.. 70 g/crn~~', lztzv.tng no exotlrerm:lc peak tzt nol; less ttran 700°C as rneasured by a da.fi'rtzc;t.Lon t;lrerrnal anal.ys.ls l.rr a.lr st;retzm, tznd coni;tzl.n:lng frorn 0.2 to 5.0 weight; % of phosphorus, tz cathode containing Li., and a non-aqueous electrolyte.
I3R_lGl? UESCI~lI'_1'ION OI'_ '1'lIE_ DRAWINGS, 2~~~~9~
Fig. 1 is a characteristic view showing ttte relation between the amount of charged phosphora.c acid and the continuous chargeable and dischargeable mA-hour as used with the resultant carbonaceous material;
FLg..2 is a cttaracterlstic view showing the relation between the amount of charged plnosphoric acid in the :L':Lred product of furfuryl alcohol resin and the residual rate o!' phosphorus;
I~.Lg. :3 :Ls a charftcterLst:Lc v.tew showing floe variation in the temperature of D't'A peak relative to tire arnount of charged phospktoric acid and Flg. 4 is a characterisl;a.c view showing the variation in doom relatl.ve to the arnount o.f charged phosphoric aced;
l~ig. 5 is a characteristic view showing a ctrargl.ng and d:Lscharg:Lng cycle character:Lst:Lc of a non-aqueous e7.ectrolyte secondary cell us.Lng F.ts Ft negat.l.ve c;:l.e,<;trade ft carbonaceous rnater.Lft:l, obtft.i.ned by rrd<t.lng ploosplrcorlc; ac;:Ld to poly:Curfiury:l. rz:l.coho:l res:ln :Ltt cornparason w:l th LhF.ti; oi' a c;e:Ll using as a negative electrode a carbonaceous rnateria:l.
obtained w:l thout addl tl.on of any phosphoric acid;
t~lg. G :Ls a charac;ter.Lst7.c v:Lew showing a dascltarge curve of a non-aqueous electro:Lyte secondary cel:1 us:l.ng a negative e:Lectrode oi' a carbanaceous material obtained by addition of phosphoric acid to polyfurfuryl a:Lcohol resin :Ln comparison w:Lth a ce:Ll us:lng a negative electrode of a _J_ carbonaceous material obtained without addition of any phosphoric acid;
Fig. 7 :Ls a char acl;erl.st:l.c view showing a discharge curve of a non-aqueous electrolyte secondary cell using a negative electrode of a c:arbonaceous mater:Lal obta:Lrzed by addition of phosphoric acid to novolac-type phenolic resin in comparison with a cell using a negative electrode of a car. bonaceous mated a:1 ob ta.l.neck w.i. tirou t tzdda. t:l.on o1' phoslrhor.k.c: ac.i.d;
Fig. 8 l.s a characteristic v:Lew show.Lng the relation between the amount of meta-phosphoric aced or pkrosphorus pentaoxade added to oxygen-crossl.lnked petrol.eurn p.Ltch and the d:Lscharge capaci ty;
Fig. y .Ls a chartzcterist:Lc view showing the var:Lat:Lon In exothermic peak ternperature o.P D'k'A when rnetrz-phosphor:Lc:
ac:Ld and phosphorus perrttzox:l dc~ are crz<:lr rzc.ldcd l;o oxygen-cross.L.Lnk<jd petro.l.r:rrm p.l tc:lr;
I~.Ig. 1.U .Ls a clraracter.i.st.i.c: v:l.ew showing t;he re;.l.ata.on between the amount or meta-phosphor.Lc ac:lck or pkrosptrorus pentaox:Lcke added to oxygen-erossl.lnked petroleum p1. tc:lr and t;he amount oi' phosphorus rema:Lning in carbonaceous material.;
k~:(.g. 11 a.s a character.Lst.Lc v.i.ew show.tng tz discharge curve of a non-aqueous electrolyte secondary cell using a negative e:Lectrode o ' a carbonaceous r«ater:La:L obta:Lned by tzckd.Ltion o.C phosphorus pentaox:Lcke t0 oxygen-cross:l.inked -g_ petroleum p9.tch in comparison with a cell using a negative electrode of a carbonaceous material obtained without addition of phosphorus pentaoxide; and Fig. 12 is a characteristic view showing a cycle , characterl.stic of a non-aqueous electrolyte secondary cel:L
using a negative electrode o~f a carbonaceous material obtained by addition of plrosplrorus pentaoxide to oxygen-cross:L:Lnked petro:Leum p:l. t<;h :l.n c;ompFZr.i.sorz wi th a ce:l:1 11~J:Lrrg Fl rt('.gF.II;.IVC' e:l.ectrUdC'. O.[' Fl carboClFlC:eouS
rTlater:la:l.
obtained without addition of phosphorus pentaox:lde.
DLSCRIP'fION OF THh PRhFERRI;D >JMBODIMEN'fS
fhe present inventors made intensive sttzd:les :Ln order to ach:Leve the above ob,Ject;s Fznd, as a result, found that the add.lt:lon of a phosphorus compound during carbonization is very effecttvE~ in Increasing the doping arnount of :L:lth.lum :Ln the resulting cFZrbona<;eous mrzter.LF.uI..
'fhe present .Lnvent.i.on .Ls Fzecompi Lslrccl bFZSCd on tlrc Fzbove .finding tzncl the carborrrzc:cous rnal;er.i.FZI oi' the l.nvent:f.on :ls characterized by car boni.zing an organ.lc mater.i.FZ:I. Fznd contain:lng U . 2 - 5 . 0 wt~ oI' phosphorus .
The proclu<:t.l.on method Fzcc;ord.lng to the :Lnventlort is characterlied in that an organic materaa:l or carbonFZC:eous material is carbonized after addition of 0.2 - 15 wt~ of a phosphorus compound, calculated as phosphorus, based on the organ.lc: rnatera.al.
_7_ A non-aqueous electrolyte cell of the :Lnvention is characterized by comprising a negative electrode consisting of a carbonaceous material obtained by carborr:iz:Lng an organic material and conta:Lnirtg 0.2 - 5.0 wt~ o.C phosphorus, a positive electrode conta:Ln:Lng I_,:1. and a non-aqueous electrolyte.
I'he carbonaceous mater:Lal o-f the lnvent:Lon :i.s obtal.ned .
by carbon:Lzat:lon, su<;lr as by a f:Lrang techna.ctue, of organ:Lc rnater.la:ls.
The starting organic rnater:Lals include any organ:Lc high molecular weight compounds including con~ugat;ed resins such as phenoli.c resins, acrylic resins, halogenated v:lnyl. res:Lns, polyarn:Lde-l.mide resins, polyam:lde resins, polyacetylene, pol(p-phenyl.ene) and the like, cellulose resins, and the lake.
l3es:Ldes , there may be t.rsed corrdcrrsrd Ioo l.yc;yc; l..l.<;
hydrocarbon <:ompouncls such txs rrttpltLltttl.enr, plretrantlrrene, anthra<:ene, triphenyl.ene, pyrene, chrysene, rraphtl~ac;erre, p:l.c:ene , pery:l.ene , pen l;aL)lrelle , lyen taeene , a tc; . arrd derivtrt:l.ves thereof' (e.g. carboxyl 1. c: acids, carboxy:L:Lc anhydr:ldes, carboxy:L:Lc acid :Lm.Ldes and the l.Lke thereof), various pitches ma:Lnly cornposed crf rn.Lxtures oi' the above compounds, and condensed heterocyllc compounds such as indole, iso-lndole, qu:Lnol9.ne, iso-qul.noline, quinoxa:L:Lrre, pht;ha:l.az.lne, c:arbazole, acrid:Lne, phenaz:Lne, phenantr:Izirre _g_ 202~~.9~.
and the like, and derivatives thereof.
In addition, Puran resins such as homopoJ_ymers and copolyrners of .furfuryl alcohol and furfural may be favorably used. More specifica:l.ly, there may be mentioned po:Lymers of furfuraJ_ + phenol, furfury:L alcohol + dimei;hyloJ.urea, ' i'urfuryl alcohol, furfuryl alcohol + rormaldehyde, furFural + ketones, and t;he lake. 'fire carbonaceous materials obtaa.rted by c;arbortLr.l.ng the furan resins hens a surface separat:Lon, dooa, at pJ.rxne (002) of not srnall.er than 3.70 angstroms and a true dens J.ty, p , ov' not larger titan 1.70 g/cm3. 'the differential thermal analysts (D'ft1) reveals that it has not any exothermic peak at temperatures not :Lower than 700°C and exh:Lb:Lis very good characteristics for use as a negative el.ect:rode for cell.
'these organic materla:l.s are tlaerrntt:l..l.y trettl;ed for carbon.Lzati.on by technictut;s such as oL' I'Lr(.rrg. 'fire t:arbon.L7Fli;aon ternperttture rutty d.l:(':I't;r dt;pcntl.l.ng on the tyke of start:lng mater.LF.t:1 and :Ls usuaJ.:l.y 1n the range <rf 500 -3000°C.
L,:Lke the furtm r.esans, when petroleurn pitches hav:Lng a spe<:lf.Lc lI/C atornac rat:Io :l.nto which funct.Lonal groups .
conta:Lrtirtg oxygen are J.ntroduc;ed (so-calaetl oxygen crossl.inkage) are cF.trbonized, good characteristics are obta:Lned. Thus, the pitches can be used as the organic mater:La.l..
_g_ The petroleum pitches are obtained by operations, such as distillation (vacuum distillation, i;opping, and steam distillatl.on), thermal polycondensation, extraction, cheml.cal polycondensation arid flue like, of tar s wh:iclr are obtained by high temperature pyrolysis of coal tsar, ethylene bottom oils, crude petroleum and the like, and asphalt.
The II/C atomic ratio of petroleum pitch :Ls important and shou:l.d be .t.n the r. ange o (' 0 . (; - () . 8 for non-graphit:lzable carbon.
The techniques of Introducing functiona:L groups containing oxygen into these petroleum patches are not critical and inc:l.ude, t'or example, a wet process us:lng an aqueous solution of nitric acid, rnixed acid, sulfuric ac:ld, hypochlorous aclcl and the :Like, a dry process using ox9.dative gases (air and oxygen) , and reac;tlons w:l th so:l.t.d reagents such as su:l.t'ur, ammon.t.r.rm nt.trrztc, r.tnnnonl.um persu:Ll'ate, I'errl.c; clr:Lor.l.dc fzrrd I;trc; :L.Ikc.
'l'lze petroleum pitclros :Lnto wll.lch oxygen-containing i'unc;t:lona:l. groups have been .Lntroduced by t;he above tec;trnidue are carbon.t.zed 1'or use as a negtzt.lve electrode rnateria:l.. '1'he carbonization cond.l t tons are not crltl.c;a1 prov.Ldecl that they are so set that the resulting <;arbonaceous rnaterial.s satisfy character:lstic requirernents that the surface separation, doo<, at (002) plane i.s not .LC:SS t;tran 3.'70 angstroms, a true derzs:Lty, p,is not larger -~.(>-than 1.70 g/cm3 and any exothermic peak by the differential thermal analysis (DTA) does not appear at temperatures of not lower than 700°C. For :Lnstance, the pitches are carbonized in a stream of nitrogen at 300 - 700°C, after wh:Lch it is fired in a stream of nitrogen under conditions of a heating rate of 1 - 20°C, an ultimate temperature of 900 - 1300°C and a time of 0 - 5 hours kept at the ultimate temperature. As a matter of course, the carbonization operation may be omitted as the case may be.
The resultant carbonaceous material serves as a negative electrode material after pulverization and classification. The pulverization may be effected prior to or after the carbonization or after the firing.
Although the carbonaceous material as stated above is described, for example, in Japanese Patent Publication No.
53-31116, the optimization of the oxygen content results in a carbonaceous material which has a surface separation, doo2, at (002) plane of not less than 3.80 angstroms and no exothermic peak at 700°C or over when determined by differential thermal analysis (DTA) in a stream of air. 'The material is used as the negative electrode material.
The content of oxygen to be incorporated in petroleum pitch greatly influences the surface separation, doo2. at the (002) plane. For instance, when the axygen content in a precursor obtained by simple crosslinkage of petroleum pitch 2022~0~.
is not less than 10 wt%, the doo2 value can be not less than 3.70 angstroms. Accordingly, the oxygen content in the precursor should preferably be not less than 10 wt~. In practice, the content 3.s in the range of 10 - 20 wt%.
)Jspecially, s.l.nce tire doo2 value o:f not less t~kian 3.72 angstroms is favorable in view of the charging and discharging efficiency, the oxygen content should be appropr:late:Ly set; wh.i.:l.e taking tkre alcove :Lnto consa.deration.
In the pra<;t:Lce ofi' the :Lnvent.ton, phosphorus compounds are added at; the time oI' the carbonization by which the dop:Lng amount of lithium in the carbonaceous materla:l can be Increased.
P~xarnples or the plrosLylrorus compound include phosphorus oxides such as phosphorus trioxide, phosphorus tetraoxade, phosphorus pentaoxide and the :Like, oxo aca.ds oC phosphorus such as ortho-phosphor.Lc r.rc; l.d ( so-crx.L:Lcd plrovplror 1. c: rxc;.l.d ) , meta-phosphoric acid, polyplrosplroric ac:Ld rrrrc:l salts of these .
oxo ac:Lds. :I:n view of the ease in hand:Ling, phosphorus oxides and phosphoric acid are preferred.
In the pract.i.ce of the .Lnvention, the arrrouIlt of phosphorus compound to be added at the t9.me o:C the CarbUniZat.lon of organ:lc rnater.la:Ls shou:l.d be 0.2 - l.5 wt%, preferab:Ly U.5 - 7 wt~, based on the organic or carbonaceous material and tyre content of phospkrorus .Ln the carbonaceous material should be 0.2 ~- 5 wt~, if the amount oi' the phosphorus compound is less than the above range and the content of phospLtorus in the carbonaceous material is too small, the effect of increasing the dop:Lng amount of lithium cannot be apprecJ.ably expected. On the contrary, when t;he amount of the phosphorus compound is too large and the content of phosphorus in the carbonaceous mater:Lal becomes too large, tLre character:Lstics become poor with t;he possib:L:L:Lty of redtrc;:Lng a rate of c;arborraceous mater:l.a:I.
wh:Lch acturz:L:l.y lakes part a.n the dop.Lng of :L J.th:Lurn.
Where the carbonaceous material i.s used as a negative electrode of non-aqueous electrolyte cell, it is preferred that the mater:Lal used for pos:l.t.lve e:Lectrode should contain a satisfactory amount of L,J.. l~or this purpose, a composite metal ox:Lde oL' the genera:l_ formula, L,iMO~, (wherein M
represents at least one of Co and Na) or layer cornpotrnds contairr:Lng L:L are used. :Ln przrt.lcul.rtr, good c;lrFtrrzctor.l.stl.c;g are obta.Lrted where us:Lng 1.,.1.(;00.
The non-aqueous e:Lectro:l.yte c;eJ.l oL' tyre irtvent.l.on a.lrns at ach.Leving h:lgh capacity wherein the posJ.t.lve e:l.ec;erode shora:l.d corrtrz.l.n L.L irr amounts c;orrespondJ.ng to a charge and d.lsclrarge capaca. ty oC not :Less tlrtzn 250 rnnLr per g oI' t;he carhona<;eous nrtzterial far negat;ive e:Lectrode :Ln stat:Lonary condition (e.g. after about f:Lve repetitions of charging and d:lscharg.Lng). L1 should preferably be contained J.n amounts c;orrespond:Lng to a c;lrarge arid discharge capacity crL' not less ~~12~i~:~.
than 300 mAh and more preferably in amounts corresponding to a charge and discharge capacity of not less than 350 mAh.
It will be noted that Li is not necessarily supplied all from the positive electrode material on the condition that Li should be present in the cell system in amounts corresponding to a charge and discharge capacity of not less than 250 mAh per g of the carbonaceous material for negative electrode. The content of Li will be determined by measurement of the discharge capacil;y of cell.
The non-aqueous electrolyte is prepared by appropriately combining organic solvents and electrolytes, and these organic solvents and electrolytes may be ones ordinarily used in this type of cell.
Examples of the organic solvent include propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, 1,2-d3ethoxyethane, y -butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 7.,3-dioxorane, 4-methyl-1,3-dioxorane, diethyl ether, sulforane, methylsulforane, acetonitrile, propionylnitrile, anisole and the like.
Examples of the electrolyte include L1C10a, LiAsF~, LiPI~~, L9.Br4, LiB(C~IIS)~, CIIaSUaLI. CF3SOsLi, LiCl.. LiDr and the like.
When a phosphorus compound such as phosphoric acid is added at the time when organic materials are carbonized into ~o~z~~~.
carbonaceous material, an amount of doping lithium becomes great, with a great efficiency as expressed by de-doping amount/doping amount.
'the use of the carbonaceous mater:Lal having great capability of doping litha.urn as.a negative e:Lectrode of non-aqueous electrolyte cell results in an increasing charge and discharge capacity wlril.e suplaressing deter:Lorat:Lon accornpan.Led by repet.l. tl.on oI' chtrrgl.ng and d:Lsclrarga.ng operations.
L ~xarnples 'fhe present invention is described based on particu7.ar experirnental results.
Preliminary C~xperiment 1 lnit.tal.ly, a furan resin was used as an organic rnateria:l to check the lnf:Luence of phosphorus be.i.ng added.
I~ig. 1. :Ls a graph show.i.rrg tlrr vur.lrrtlorr of rr conta.rruous chargeable and dischargeab:l.e; furl[)ere-frour/g re.lat:lve to tire arnount of charged. phosphoric acid with respect to a ce:Ll wh.tcli makes use of a negat:Lve electrode whlc;h is obta.tned by C.I,r:l.ng a po:Lyfurl'ury:l. a:LcUllol res:Ln (rna:Le:lc anhydr:Lde catalyst) wlr.L:l.e add:lng phosphoric trcl.d. L~rorn th.Ls, :Lt wi:l:L
be seen thal; tire addit:ton or phosphoric ac:Ld upon .L':Lr:lng is very effective in increasing the charge and discharge capacity.
The added phosphorus cornpouncl was Ieft :Ln the resu:Lting 2~~~~~~
carbonaceous material as is shown in I'9.g. 2. :Lt will be noted that the amount of phosphorus in the carbonaceous rnaterial was quantitai;lvely determl.ned by an induct:lvely coupled plasma (1CP) spectrometry.
The fired product of the po:LyfurCuryl alcohol resin Itas not exotherrrtlc peak at 700°C or over when determined by I)TO
and has a surface separation, doom, at (002) plane of as :Large F,ts ,i.8 5 angstrorns. Wlrrn pltosphor.tc acl.cl was added dur:l.ng f:lrirrg o.f' the po:lyfurfuryl a:lcolro:l resin, l:Ltt;:le variation in the characteristics is observed as shown i.n Figs. 3 and 4. For :Lrrstance, the addition of 1.0 wt~ of phosphoric acl d entails an exotherrn:Ic: peak of F.rpproxarnately 680°C determined by D'fA and a cloo2 value of not :Less than 3.70 angstrorns.
By this, it was confirmed drat the add:l.Laon o(' Ltm phosphorus compound cl:l.d not Lmped<; t;tro <slntrrrc;Lcr.l.st.l<;s a.nherent to the r;arborrucoous mat;erlfrl..
Based on the results of the above Prelirn:lnary L:xarnp:l.e 7., a cell usl.ng a negative electrode made o!' a carbonaceous rnater:la:l which h:xd been obLalrred by !':l.r:tng a .Curan res:Ln to wlr:L<;h a phosphorus compound was added was assembled to evaluate its character-istlcs.
Example 1 500 g of furfuryl alcohol, 1 g of maleac anhyclrade and 200 g of pure water were rnlxed acrd refluxed on a hot water -lf-~~<~~~~~
bath for 2 hours to obtain a viscous polymer.
lifter removal of unreacted alcohol and residual water by vacuum distillation, 5 g of a 85~ phosphoric acid (II~PO") aqueous so,lut:Lon was added to 100 g of the polymer.
This was maintained for carboriazation :Ln a stream of nitrogen at 500°C for 5 hours, Followed by heating to 1200°C
and thermal treatment for 1 hour. The resultart carbon ace0us rnater:la:1 had the vl'o.l.:l.ow.l.ng c;hfzracterista.cs.
cloo2 = 3.82 rzngstrorns true density, p, - 1.55 g/crn3 exothermic peak by 1)T'A: 643°C
phosphorus content . aborzt 1.4 wt~
The thus obta.Lned carbonaceous mal;er.lal was used to const:ltute a cell as !'oll0ws.
The carbonaceous rnateria:L was lnj.t:La:Lly powdered by means of a rnorta .r anti c;.Lflss L C:led thr0uglr rz s.i.evc to c;o:l.:l.e;c: l;
part;ic:Les wLth a sloe o.L' ;l f)0 m-esh or be:l.ow.
1.00 rng of polyvi.nyl.idene f:l.uoride used as a b.lnder was added t0 :1 g of the classified carbonaceous mtzter-i.tz:L, and d.Lrnetlzy:l.Cormam-i.de was used Lo make a paste. i'ol:Lowed by app:l.lcrztaon to a sta:lnless steel. gauze and pressing at a pressure of 5 tor5s/crn?. The app.L.l.ed gauze was punt;hed Into a suitable form for use as a negative e:l.ectrode.
l1 positive electrode was made using LiN.io. 2t%oo, ~Oe in the fo:ll.owing manner.
_17_ 2Q~2~~~.
600 mg o.P graphite and 300 mg of polyethylene tetrafluoride were added to and mixed with 9.1 g of LiNio.2Coo.~02, after which 1 g of the mixture was placed in a mold and subjected to compression molding at a pressure of 2 tons/cm2 to obtain an electrode of a disk shape.
The thus obtained pos:Ltive and negata.ve electrodes were used and a'solution of 1 rnole/1 of LiGlO" in a mixed so:l.ution of propylene <;arbonate-da.rnethoxyet;hane (ratio by vo:Lurne o.(' 1 :.1. ) wFts used to rnake a co:In-shaped cell. for a charge and discharge test.
'fhe cell was arranged so that the arnount of. active substance was positive electrode » negative e:Lectrocle .C.rom the standpoint o:f e7.ectrochem:Lca1 equivalence, and the cell capacity was regulated at the negative electrode. In the charge and d.ischrzrge test, charging and discharg.lng were conducted at; a constant current; (0.5,3 rM/cm' ) .
'fhe ce:l.l wus clrargnd rtl; ,320, 350 r~n<l 380 rnAll/g (c;hu.rged rnA-hour per g of the carbonaceous material lterea.n etnd whenever it appears hereinafter) , wherein when a da.scharge cu l;-off vo:ltftge was set; ttt .1.5 V under wh.LCh a cycle test was effected, a good cyc7.e characterist:Ic was obtained in al:L the cases. :Crt I~ig. 5, the curve :L shows the characteristic obtalne<I by cltarg:lng at 380 mOII/g. The cell of this example d.ld not deterl.orate over 80 c:yc:les when charged at 380 rnllll/g.
2~~~:~~~.
Accordingly, it will be seen that the cell of ttr:Is example is chargeable or dlschargeable at a capacity which is higher than the theoretical in the case of graphite used as the~~negative electrode.
Iri Fig. 6, there i.s shown a discharge curve when the cell is charged at 380 mAIt/g (solid curve i.n the figure).
1'tre cell of th:Is example brad a charge and discharge e1't'lcJ.ency of 98.5% wltlr good results.
Cornparatlve ExtzmPle-1 After obtaining the polymer in the same manner as in Example 1, it was thermally treated without addition of any ptrosphorl.c acid to obtain a carbonaceous material.
'1'hls carbonaceous mater:Lal was used to make a cell in the same rnanner as Ln Example 1. The results of the cYrarge and discharge test are shown :ln I?:Ig. 5. f.rr F:Lg. 5, curve :L.i.
is a cycle charrrcterlsl;.i.c In tire rttsc; ol' <;lrrrrg,l.trg at 3130 rnAll/g, curve ll.l Ls a cycle clrarrr<;terlst.tc; .i.n. the case o~f chargl.rrg at 350 mAII/g and curve lv :Ls a cyc:l.e chara<;ter l.st.i.c :Ln the case of charging at 380 rnAl1/g.
:It; wl.:l.:l be seem that; a stab:l.e cycle characterast:l.c :Ls :L:LrnJ.ted only to the case where the c;hFrrged arnpere-tuour is approxlrnately 320 mAll/g.
1'he discharge curve when charged at 320 mAII/g is shown in F.ig. 6 (broken-line curvo l.n the f:Igure) . The charge ~znd d:Ischarge eff.lclency :Ls approxlrnatel.y 97%.
In order to confirm the effect of the case using other resin, a cell was s9.milarly assernbled using a novolac-type phenolic resin to evaluate its characteristics.
IJxample 2 g of pure water and 1 g of ethanol were added to 1.0 g of a novolac-type plrenollc resin powder (~PGA 4552 B, available from Gune:L Chern. Co. , Ltd. ) and wetted, after wh.Lc:h 5UU mg of a ti5°~ phosplu>rJ.c; acJ.d aqueous so:Lution was added and well mixed.
After keeping the mixture in a strearn of nitrogen at ' 500°C 'for 5 hours, it was heated up to 1200°C and thermal:Ly treated for 1 hour to obtain a carbonaceous rnater:lal. '.l'he thus obtained carbonaceous material had the following characteristics.
done = 3.75 angst;rums pure density, p , _ .1..60 g/em'' exothermic Iaeak by n~rA = (131°C
content of phosphorus: about 1.4 wt~
'fhe thUS UbtFl:lrred carbonaceous material Was used tU
make a ceJ.J. :Ln the carne manner as In hxamp:Le 1.
As a result of the charge and d:Lscharge test at dift'erent charged and discharged arrr.pere-hours, it was found that stable charging and dlsclnarging operations were ensured at a charged amount o:C not higher than 360 rnAII/g.
'.1'he cl.lsclrar-ge curve wherein charging was effected at 360 mAH/g is shown in Fig. 7 as a so:L:Ld line. In this case, the charge and discharge efficiency was 98%.
Comparative )xample 2 In the same manner as in );xample 2 except that phosphor..ic acid was not added to the novolac-type phenol resin powder, there was made a cell, followed by a charge and discharge cycle test at different charged amounts.
/1s a result, stable operat:Lons o:f charga.ng and d:Lscharg:Lng were :L.Lmi.ted to tire case where tire charged amount was at rnost ZJ.O rnAll/g.
'fhe discharge curve where charging was e.P:fected at 21.0 mAII/g 1s shown in Fig. 7 as a broken line. 'fhe charge and discharge efr'lcaency was approxirnatei.y 95%.
As wiJ..L become apparent from the above examples and comparat:Lve examples, carbonaceous materials ensuring a remarkably lrnproved charge and cL:Lsc;htzrge crzprzc;.l. ty ove;r known counterpfzrts can be cjbtn.Lnc;cL by tzdcJ:l.tion crI' hhosluhor.lc; ac;.Lcl.
)Jspec.La:l.J.y, tzs is descr.Lbed .Lrl Isxamp:l.r, 1., there cart be obtalrred a carbonaceous mater:Lal, depend.Lng on the type of star. tang rnater.ta:l., wltJ.ch htzS Fz c;barge and discharge capacity hJ.gher than tire theoretical. rzs expected by graphJ.te.
1'rellrnlnarv Lxperimerrt 2 Inltla:L:l.y, petro:Leurn pitctr (II/C atornac ratio of 0.6 -0.8) was oxidized to provide a carbon precursor having an oxygen content of 15.4 wt%. 'fo the precursor were added 2Q~z~~
various phosphorus compounds (ortho-phosphoric acid, phosphoric anhydride (phosphorus pentaoxide) and various phosphorates), followed by carbonization in a stream of nitrogen. at 500° for 5 hours.
flrer,eafter, the carbonized beads were powdered :Ln a mill arid charged into a crucible, fo:Llowed by faring in a stream of nitrogen at a heating rate of 5°C/minute at an ul.ta.rnate ternperrzture of 1.1.00°C for tx t:Lme oC :1. hour :for wh.i.ch the u:l.tLrnate temperature was rnaanta.ined.
/liter cooling, the product was powdered and classiried through a mesh to a size o-f not larger than 38,u m.
'these carbonaceous materials were eva:l.ttated t.rs:l.ng test cel:l.s.
t~or the fabr.i.cation of the test cell, the carbonaceous materials were, respectively, pre-heated, 7.mmediately prior to preparat.l.on o:f a rn:l.x for negrxt.Lve r:l.ec;trocle, irr Ft strertm of Ar under cond.l t.Lons of a hr~rtt.(rrg rrtte of about 30°C/rnlntrte, a ternperature crf 600°C and a lto:l.d:lng t.i.rne a.f 1 hour at the temperature. Thereafter, pol.yvanylidene f:lttor:lde used as tt binder was added to the material :Ln an amount of :1.0 wt~s based on the carbonaceous material, fol:lowed by rn:Lx.tng wl th d.lrnethy:l..('orrnarn.lde solvent and drying to obtain a negative electrode mix. Subsequently, 37 mg of the mix was molded along with a Ni mesh used as a current coll.ec;tor into a pellet with a diarneter o-f 15.5 rnrn, thereby 2~~,~~.~~.
obtaining a carbon electrode. The test cell had the following arrangement.
Cell arrangement coin-shaped cell (da.arneter of 20 mm, thickness oi' 2.5 rnm ) counter electrode : L, L metal separator: porous fil.rn (polypropy:l.ene) e:Lectro:l.yt;e: 1 rnoJ.e/:1. oC 1.,:1.C:L f)" ei:Lsso:Lved in a m:Lxed so:Lvent ( 1 : 1 by vo:Lurne) o.C propy.lene carbonate and me tlroxye thane current collector: copper foil The test cell with the above arrangernent was repeate<l.ly charged and discharged five t:Lrnes and .reached a stat:Lonary state, wlner.eupon a dJ.scharge capacity per g of the carbonaceous material const;it;tzting the carbon electrode was measured. 'fhe dop:lng of i.l.l;ha.um .i.n Llrc-~ crtrbon r,LecLroclo (c;harging: st;r.l,ctly c~peak.l.rrg, rza.l,horz~;h l;trr,, process of dop:l.ng Ln carbort in th:ls test method a.s not; charging but;
discharging, the doplng process is ca:L:l.ed clrarg:lng and tyre de-dopa.n6r process is caJ.led dasc;ttarging only for convenience' sake J.n v.Lew oC Lyre sa.Luat:Lon of actual cell) was performed at a current; density of 0. 53 rnll/crn~ by repetl.t.Lon of the cycle of one hour charging/two-hour L~reak until a balanced voltage reached 0 at the time of the break. 'fhe d:Lscharge (de-dopJ.ng of 7..Lthium -from the carbon) was performed at a ~fl2~1~~
current density of 0.53 mA/cm2 by repetition o.t' 1 hour discharging/two-hour break wherein a terminal voltage of 1.5 V was determined as a cut-off voltage.
As a result, all the phosphorus compounds could improve the discharge capacity of the carbonaceous material and the effect o'f the addition was in the order o-f anhydride>pllosphor:Lc aca.d>mUnobasi.c salt>ct:(. bas:(.c sa:l.t.
t~ig. 8 :Ls a clraractera.st.(.c v:Lew showing the re:latJ.orr between the arnount UI' phosphorus compounds (phosphorus pentaoxide and meta-phosphoric acid) added to the carbon precursor and the discharge capac:Lty. With meta-phosphor:tc acid, the discharge capacity becomes rnaxLmF.r:l. when tyre ac.tci is added in about 5 wt°~, over which it is kept almost constant. On the other brand, the capacity becomes rnaxirnal at 10 wt~ for phosphorus pentaoxide, UVer wha.<;h t;he discharge captlc:ity :Ls lowcrcd. The compara.son beLwc)rn meta-phospbror:Lc acid and phosphorus pentaox.l.de revea.l.s that the :Latter has a greater effect.
:!n '1'ab7.e 1., there is shown the cb:Lscharge capacity i11 cage Wblere typ:LCfll plrU9p11Urr1S CUtllpUllrldS are added.
Table 1 Phosphorus Compound Amount (wt~) Discharge Capacity (mnh~g) NaalIP03 ~ 5II~0 8.8 388 Na~HPOn ~ 2II20 6.7 431 P206 (dry) 5.8 494 I'~Oes + IIaO 5.8 466 II;iPOn 4. U 4;i(i When the car~tionaceaus material :Ls used as the; rrc~~at;ive e:lectracle of non-aqueous electrolyte cell, the surl'ac;e separat:larr (door) of the carbonaceous mater:la:L and the exotherm.i.c peak temperature ('1'p) apperxr:lng :ln the D'.I'A curve Ls considered to have floe c:Lose relata.an w:l tlr the cell.
characterlst.lcs.
Accordingly, how doa2 and '1'p are varied by the addition of a phosphorus campauncl and t;he relation het;ween Lhe _z5_ characteristics and the variations were determined.
As a result, it was found that doo2 = 3.73 angstroms when meta-phosphoric acid was added in 2 wt%, doo2 = 3.71 angstroms when added in 4 wt%, doo2 = 3.73 angstroms when added in 6 wt%, and doo2 = 3.71 angstroms when phosphorus pentaoxide was added in 6 wt%: The exotherm:Lc peak temperature in the D'1'A curve was changed as shown 9.n Fi.g. 9.
:l:n v:lew oC these resu:Lts, I;ire var:LtzL:i.ons o.C tire respec;t.Lve parameters caused by tire addition of the pltosphorus cornpourtds are not so prorraunced and the improvements of the character:lstics are not; da.rect:Ly proportional to the variat:Lons of the parameters, other factors being assumed to contribut;e t;o t;he irnprovements.
Moreover, the relation between the phospharus cornpounds bea.ng added and t;he content of phosphorus left in the carbonaceous rnatesra.a:l. was deterrn:l.ned. 'I'ltc r<;yl,dua.L rtrnourtt of phosphorus was nreasurc;d Ln rite same manner fzs a.n Prelim:Lnary Cxperirnent 1. The resu:l.ts are shown in P:Lg. 10.
As the amount of the phosphorus compound .Lnc.reases, the content of phosphorus left :(.n the carbona<;eons materia:L
eventua:L:l.y increases, with Lhe tendency that the res:Ldua:L
arnount; of phosphorus :Ls saturated aL approximately 3 wt%.
According:ly, the amount of phosphorus left in carbonaceous mater:Lal. should preferably be O.L - 3 wt%, more preferab:l.y U.5 - 5 wt%.
2~~~~.~~.
Based on the results of the above Preliminary Experiment, a carbonaceous material which had been fired by adding a phosphorus to a carbon precursor obtained by introducing an oxygen-containing functional group into petroleum p:itch was used to assemble a non-aqueous secondary cell for determination of its characteristics.
Example 3 I1 petroleurn p:1 tch whose I1/C atomic rat:Lo was appropr:l.ate7.y se7.ected from a range of U.6 - U.8 was broken into pieces and sub,~ected to oxidation treatment in a stream of oxygen to obtain a carbon precursor. The carbon precursor had a quinolirre insoluble content (centr9.fugal method by J1S: K2425-1983) o.f 8U% and an oxygen content (by organic element analysis) of 15.4 wt~.
6 wt% of phosphorus pentaoxide (P208 was added to tire carbon precursor, wha.ch was carborr:Lzed .Ln rr sl;ream oI' nitrogen nt 5UU° I'or 5 hours, i'o.L:l.owc~d by heFrt:Irrg Lo li.UU°C
for 1 hour.
The resultant carbonaceous mal;eria:l. was used to constitute a ce:Ll as .fo:L7.ows.
The carbonaceous rnaterial was initial.:ly powdered by means of a rnortar and classified through a s:Leve to collect particles with a size of 39U mesh or below.
lU0 mg of polyvinylidene fluoride used as a binder was added to 1. g of the carbonic;eons mat-er:lal, and _27-~02219~.
dimethylformamide was used to make a paste, followed by application to a stainless steel gauze, drying and pressing at a pressure of 5 tons/cm2. The applied gauze was punched into a suitable form for use as a negative electrode. The net weight of the carbonaceous material was 32.4 mg.
A positive electrode was made using LiNio.2Coo:e02 as art act9.ve substance. 6 g of graphite and 3 g o.C
polyethylene teLraf:Luor:Lde were added to arid we:l:L mixed whit 91 g of L:LN:Lo. aCoo. e0a, after which 1 g of the mixture was Placed in a mold and subjected to compression molding at a pressure of 2 tons/cm2 to obtain an electrode of a disk shape.
1'he thus obtained positive and negative electrodes were used. A solution of 1 rnole/:L of LiC104 in a mixed solution of propylene carbonate-1,2-dimethoxyethane (ratio by volume of 1:1) and a poiypropy:lene non-woven frtbr:l.c wc;ro usctd l,o make a coin-shaped ce:Ll. 'l'ltc cel:L rnacln use of the actl.ve substance :Ln such an amount that positive electrode»negat.Lve electrode from the standpoirtL of the e:Lectrochemica7. eduiva:l.ence as regulated by the negat:Lve e:Lectrode.
Comparative Example 3 In the same manner as in Exarnple 3 except that phosphorus pentaoxlde was not added upon carbonization of the carbon precursor, there was obtained a coin-shaped cell.
With regard to Example 3 and Comparative Example 3, discharge curves were drawn. 'fhe results are shown i.n Fig.
11. In the figure, the solid line indicates the discharge curve of Example 3 and the broken line ind.tcates the discharge curve of Comparat9.ve Example 3.
From F:Ig. 11, :Lt wall be seen that the cell using the fired product to wh:lch the phosphorus compound as added 1s s:IgnJ, f:l.c;anl;:ly better, wi th respec; t; to t;lre capac:l ty.
'fhe celi.s of Exarnp:le 3 tznd Comparat:lve Exarnple 3 were sub,Jected to deterrn:kned of a cycle characteristic. In the charge and discharge test, the current density was 0.53 mA/cm2 for. both charge and discharge under a consl;ant;
current and the cut-off voltage of the d:lsclrarge was set at 1..5 V. The resu7_ts are shown in Fig. J.2.
:l:n rig. 12, lane a Ls a cycle character:lstic a.n case, where the cell. ofi Exarnp:l.e ;; wrzy c;hrzrgcck rzt 3(i0 rnAlr/g, l..l.ne b is a cyc;i.e. clrFrrnc;tnr.l.~rt.l <; Ln crzyr whcrc; t;lre c;c l .l. of Comparat:l.ve Cxarnple 3 was charged at 360 rnAlr/g and :Line c; a.s a cycle c;harac;ter:l.sti.c in case where the cell. of Comparative Example 3 was charged tzt 320 mAh/g.
With the ce:il of Example 3, t exh:Lbits a good cycle character:Lstic when charged at 360 rnAh/g. In Comparative Example 3, the life 1s very short. When the cell of Cornparati.ve Example 3 was charged at 320 m/1h/g, a good cycle charrzcter:i.st:lc is obt;ai.ned lrut Che dl.scharge capac:lty is small.
Specific examples of the invention are described, which should not be construed as limit:Lng the invention thereto.
Various varaat.ions rnay be poss:Lb:Le wl.thout departing .Prom the scope of the invent:Lon.
As will be apparent from the foregoing, the carbonaceous rnater:Lal. of i;he :l.nventa.on contrz:Lns pkrosphorus rznd the present :l.nvention can provl.de a carbonaceous mater:lal capab:Le of dop:Lng :Lathiurn in large amounts.
According to the method of the invent.ton, there ca.n be prepared a carbonaceous material tray:lng good c;harrzcter.lstics by a sample procedure and espec:La:Lly a carbonaceous mater:La:1 which ttas great capability of doping lithium and a good charge and dlsclzarge effi.rl.ency (de-doping/doping amounts).
In the non-aqueous el.ect;ro:l.yte c;e:l.:l. of the .Lnventl.c~rt, the carbonaceous rnater l.rza Irrzv.l.ry grE;rtl; caprztr:L:l. i ty oC
dop.l.ng litlrl.um and a good charge and cl:Lscharge el'C:lc.lency .Ls used as a negative electrode whereby one can rea:L:lze a charge and d:Lscharge c;apac.Lty wir.lc;h .l.s lt.l.gher than tkze theoretical as :In aloe case us.lng graphite rzs a negative electrode. 'thus, .Lt :ks poss.Lbl.e to provide the ce:l.:l. havl.ng excellent cycle characteristics and an excellent charge and discharge efficiency.
It is accepted that these are all ascribed to the lithium rnetal, resulting from the change in shape of the lithium negative electrode, the formation of dendrite and the inactivation of lithium accompanied by the repetition of charging and discharging.
One measure for solving the above problem, there has been proposed the use of a negative electrode wherein lithium is not used as a single material but :Ls doped with a carbonaceous material. This makes use of easy electrochemical formation of rx carbon layer. compound of lithium. ror instance, when a carbonaceous rnateri.al used as a negative electrode is charged :Ln non-aqueous electrolyte solution, lithiurn in the positive electrode :Ls electrochemically doped in the :Lnterlayers of tLre negative carbon. 'fh<s :L a.thiurn-Japed c;arban acts as rr 1:l.thiurn electrode and the l:Lth:lum 1s de-doped from the carbon interlayers upon discharge, returning Lo tire positive electrode.
'fhe electric capacity per unit we:Lglrt a.f.' tyre carbonaceaus materia:L is determ:Lned depending on the amount of doped l:Lthiurn. In order to increase the charge and discharge capacivty, it :Ls des:Lrab:Le to .Lrrcrrase tlrc anraunt of doped I,LtIr.Lurn as :Large, rm pass l.b_Lc;. ('1'Irn tlnoorc3l;.l.crrJ.
ulrlaer lim:l.t ie a rate of one 1_..L acorn per 6 crtrbon atoms. ) II.Ltherto, the carbonaceous rnater:l.al used as the negat:Lve elecLrad a of this type of ce:l:L includes <;arbanaceaus mater lals abi;a.Lned :('ram organ:lc materia:Ls as is known, for examp:Le, i'rom Japanese Laid-open 1'aterrt Application No. 62-122066 or No. 62-90863.
Ilowever, the amount of doped lithium a.n the hittrerto known carbonaceous rnaterlals Ls not; so high that it i_s only 2~~~~~
approximately half the theoretical.
OBJECTS AND SUMMARY IF 1'lIE INVENTION
It; is arz object of the present invention Lo provide a carbonaceous materl.a:L hav:Lng a large doping capac:Lty 'for Li .
I1; l.s another object of the present :Lnvent:lon t;o provide an improved non-aducous e:Lect;rolyt;e cel:L hav:i.ng large capacity and improved charge-discharge cycle charac;ter:l.si.c;s.
Occ;orcl:lng Lo one, aspect oi' the pr-rsent; lnverrtion, there is provided a carbonaceous material having an :Lnterlayer spac:lng, doo2, of not less tharr 3.70 angstroms and a true density of less than 1.70 g/crn' , having no exotlrerm:lc peak at not :Less than 700°C as measured by a dt.Crractaou thermal analys.l.s l.n air st;retzrn, and containing from 0.2 to 5.0 weight % of phosphorus.
According Yo tznot;her aslyect; of I;he prr,sc;nt; Lrrvcnt;.f.orr, there .Ls a.l.go prov.i.ded tz uorr--tzclur,«riv a l.r,<;l;ro.lytc cc; l.:l.
wlr lc;lr comprises till fzllUde Ot' a c;arborrac;eorrs muter ltz:1 hav.l.rrg tzn an a.nter:Layer spac.tng, doom, of not less thtzn 3.70 angstrorns tzncl tz true dens.i. t;y of :Less t;trtzn 1.. 70 g/crn~~', lztzv.tng no exotlrerm:lc peak tzt nol; less ttran 700°C as rneasured by a da.fi'rtzc;t.Lon t;lrerrnal anal.ys.ls l.rr a.lr st;retzm, tznd coni;tzl.n:lng frorn 0.2 to 5.0 weight; % of phosphorus, tz cathode containing Li., and a non-aqueous electrolyte.
I3R_lGl? UESCI~lI'_1'ION OI'_ '1'lIE_ DRAWINGS, 2~~~~9~
Fig. 1 is a characteristic view showing ttte relation between the amount of charged phosphora.c acid and the continuous chargeable and dischargeable mA-hour as used with the resultant carbonaceous material;
FLg..2 is a cttaracterlstic view showing the relation between the amount of charged plnosphoric acid in the :L':Lred product of furfuryl alcohol resin and the residual rate o!' phosphorus;
I~.Lg. :3 :Ls a charftcterLst:Lc v.tew showing floe variation in the temperature of D't'A peak relative to tire arnount of charged phospktoric acid and Flg. 4 is a characterisl;a.c view showing the variation in doom relatl.ve to the arnount o.f charged phosphoric aced;
l~ig. 5 is a characteristic view showing a ctrargl.ng and d:Lscharg:Lng cycle character:Lst:Lc of a non-aqueous e7.ectrolyte secondary cell us.Lng F.ts Ft negat.l.ve c;:l.e,<;trade ft carbonaceous rnater.Lft:l, obtft.i.ned by rrd<t.lng ploosplrcorlc; ac;:Ld to poly:Curfiury:l. rz:l.coho:l res:ln :Ltt cornparason w:l th LhF.ti; oi' a c;e:Ll using as a negative electrode a carbonaceous rnateria:l.
obtained w:l thout addl tl.on of any phosphoric acid;
t~lg. G :Ls a charac;ter.Lst7.c v:Lew showing a dascltarge curve of a non-aqueous electro:Lyte secondary cel:1 us:l.ng a negative e:Lectrode oi' a carbanaceous material obtained by addition of phosphoric acid to polyfurfuryl a:Lcohol resin :Ln comparison w:Lth a ce:Ll us:lng a negative electrode of a _J_ carbonaceous material obtained without addition of any phosphoric acid;
Fig. 7 :Ls a char acl;erl.st:l.c view showing a discharge curve of a non-aqueous electrolyte secondary cell using a negative electrode of a c:arbonaceous mater:Lal obta:Lrzed by addition of phosphoric acid to novolac-type phenolic resin in comparison with a cell using a negative electrode of a car. bonaceous mated a:1 ob ta.l.neck w.i. tirou t tzdda. t:l.on o1' phoslrhor.k.c: ac.i.d;
Fig. 8 l.s a characteristic v:Lew show.Lng the relation between the amount of meta-phosphoric aced or pkrosphorus pentaoxade added to oxygen-crossl.lnked petrol.eurn p.Ltch and the d:Lscharge capaci ty;
Fig. y .Ls a chartzcterist:Lc view showing the var:Lat:Lon In exothermic peak ternperature o.P D'k'A when rnetrz-phosphor:Lc:
ac:Ld and phosphorus perrttzox:l dc~ are crz<:lr rzc.ldcd l;o oxygen-cross.L.Lnk<jd petro.l.r:rrm p.l tc:lr;
I~.Ig. 1.U .Ls a clraracter.i.st.i.c: v:l.ew showing t;he re;.l.ata.on between the amount or meta-phosphor.Lc ac:lck or pkrosptrorus pentaox:Lcke added to oxygen-erossl.lnked petroleum p1. tc:lr and t;he amount oi' phosphorus rema:Lning in carbonaceous material.;
k~:(.g. 11 a.s a character.Lst.Lc v.i.ew show.tng tz discharge curve of a non-aqueous electrolyte secondary cell using a negative e:Lectrode o ' a carbonaceous r«ater:La:L obta:Lned by tzckd.Ltion o.C phosphorus pentaox:Lcke t0 oxygen-cross:l.inked -g_ petroleum p9.tch in comparison with a cell using a negative electrode of a carbonaceous material obtained without addition of phosphorus pentaoxide; and Fig. 12 is a characteristic view showing a cycle , characterl.stic of a non-aqueous electrolyte secondary cel:L
using a negative electrode o~f a carbonaceous material obtained by addition of plrosplrorus pentaoxide to oxygen-cross:L:Lnked petro:Leum p:l. t<;h :l.n c;ompFZr.i.sorz wi th a ce:l:1 11~J:Lrrg Fl rt('.gF.II;.IVC' e:l.ectrUdC'. O.[' Fl carboClFlC:eouS
rTlater:la:l.
obtained without addition of phosphorus pentaox:lde.
DLSCRIP'fION OF THh PRhFERRI;D >JMBODIMEN'fS
fhe present inventors made intensive sttzd:les :Ln order to ach:Leve the above ob,Ject;s Fznd, as a result, found that the add.lt:lon of a phosphorus compound during carbonization is very effecttvE~ in Increasing the doping arnount of :L:lth.lum :Ln the resulting cFZrbona<;eous mrzter.LF.uI..
'fhe present .Lnvent.i.on .Ls Fzecompi Lslrccl bFZSCd on tlrc Fzbove .finding tzncl the carborrrzc:cous rnal;er.i.FZI oi' the l.nvent:f.on :ls characterized by car boni.zing an organ.lc mater.i.FZ:I. Fznd contain:lng U . 2 - 5 . 0 wt~ oI' phosphorus .
The proclu<:t.l.on method Fzcc;ord.lng to the :Lnventlort is characterlied in that an organic materaa:l or carbonFZC:eous material is carbonized after addition of 0.2 - 15 wt~ of a phosphorus compound, calculated as phosphorus, based on the organ.lc: rnatera.al.
_7_ A non-aqueous electrolyte cell of the :Lnvention is characterized by comprising a negative electrode consisting of a carbonaceous material obtained by carborr:iz:Lng an organic material and conta:Lnirtg 0.2 - 5.0 wt~ o.C phosphorus, a positive electrode conta:Ln:Lng I_,:1. and a non-aqueous electrolyte.
I'he carbonaceous mater:Lal o-f the lnvent:Lon :i.s obtal.ned .
by carbon:Lzat:lon, su<;lr as by a f:Lrang techna.ctue, of organ:Lc rnater.la:ls.
The starting organic rnater:Lals include any organ:Lc high molecular weight compounds including con~ugat;ed resins such as phenoli.c resins, acrylic resins, halogenated v:lnyl. res:Lns, polyarn:Lde-l.mide resins, polyam:lde resins, polyacetylene, pol(p-phenyl.ene) and the like, cellulose resins, and the lake.
l3es:Ldes , there may be t.rsed corrdcrrsrd Ioo l.yc;yc; l..l.<;
hydrocarbon <:ompouncls such txs rrttpltLltttl.enr, plretrantlrrene, anthra<:ene, triphenyl.ene, pyrene, chrysene, rraphtl~ac;erre, p:l.c:ene , pery:l.ene , pen l;aL)lrelle , lyen taeene , a tc; . arrd derivtrt:l.ves thereof' (e.g. carboxyl 1. c: acids, carboxy:L:Lc anhydr:ldes, carboxy:L:Lc acid :Lm.Ldes and the l.Lke thereof), various pitches ma:Lnly cornposed crf rn.Lxtures oi' the above compounds, and condensed heterocyllc compounds such as indole, iso-lndole, qu:Lnol9.ne, iso-qul.noline, quinoxa:L:Lrre, pht;ha:l.az.lne, c:arbazole, acrid:Lne, phenaz:Lne, phenantr:Izirre _g_ 202~~.9~.
and the like, and derivatives thereof.
In addition, Puran resins such as homopoJ_ymers and copolyrners of .furfuryl alcohol and furfural may be favorably used. More specifica:l.ly, there may be mentioned po:Lymers of furfuraJ_ + phenol, furfury:L alcohol + dimei;hyloJ.urea, ' i'urfuryl alcohol, furfuryl alcohol + rormaldehyde, furFural + ketones, and t;he lake. 'fire carbonaceous materials obtaa.rted by c;arbortLr.l.ng the furan resins hens a surface separat:Lon, dooa, at pJ.rxne (002) of not srnall.er than 3.70 angstroms and a true dens J.ty, p , ov' not larger titan 1.70 g/cm3. 'the differential thermal analysts (D'ft1) reveals that it has not any exothermic peak at temperatures not :Lower than 700°C and exh:Lb:Lis very good characteristics for use as a negative el.ect:rode for cell.
'these organic materla:l.s are tlaerrntt:l..l.y trettl;ed for carbon.Lzati.on by technictut;s such as oL' I'Lr(.rrg. 'fire t:arbon.L7Fli;aon ternperttture rutty d.l:(':I't;r dt;pcntl.l.ng on the tyke of start:lng mater.LF.t:1 and :Ls usuaJ.:l.y 1n the range <rf 500 -3000°C.
L,:Lke the furtm r.esans, when petroleurn pitches hav:Lng a spe<:lf.Lc lI/C atornac rat:Io :l.nto which funct.Lonal groups .
conta:Lrtirtg oxygen are J.ntroduc;ed (so-calaetl oxygen crossl.inkage) are cF.trbonized, good characteristics are obta:Lned. Thus, the pitches can be used as the organic mater:La.l..
_g_ The petroleum pitches are obtained by operations, such as distillation (vacuum distillation, i;opping, and steam distillatl.on), thermal polycondensation, extraction, cheml.cal polycondensation arid flue like, of tar s wh:iclr are obtained by high temperature pyrolysis of coal tsar, ethylene bottom oils, crude petroleum and the like, and asphalt.
The II/C atomic ratio of petroleum pitch :Ls important and shou:l.d be .t.n the r. ange o (' 0 . (; - () . 8 for non-graphit:lzable carbon.
The techniques of Introducing functiona:L groups containing oxygen into these petroleum patches are not critical and inc:l.ude, t'or example, a wet process us:lng an aqueous solution of nitric acid, rnixed acid, sulfuric ac:ld, hypochlorous aclcl and the :Like, a dry process using ox9.dative gases (air and oxygen) , and reac;tlons w:l th so:l.t.d reagents such as su:l.t'ur, ammon.t.r.rm nt.trrztc, r.tnnnonl.um persu:Ll'ate, I'errl.c; clr:Lor.l.dc fzrrd I;trc; :L.Ikc.
'l'lze petroleum pitclros :Lnto wll.lch oxygen-containing i'unc;t:lona:l. groups have been .Lntroduced by t;he above tec;trnidue are carbon.t.zed 1'or use as a negtzt.lve electrode rnateria:l.. '1'he carbonization cond.l t tons are not crltl.c;a1 prov.Ldecl that they are so set that the resulting <;arbonaceous rnaterial.s satisfy character:lstic requirernents that the surface separation, doo<, at (002) plane i.s not .LC:SS t;tran 3.'70 angstroms, a true derzs:Lty, p,is not larger -~.(>-than 1.70 g/cm3 and any exothermic peak by the differential thermal analysis (DTA) does not appear at temperatures of not lower than 700°C. For :Lnstance, the pitches are carbonized in a stream of nitrogen at 300 - 700°C, after wh:Lch it is fired in a stream of nitrogen under conditions of a heating rate of 1 - 20°C, an ultimate temperature of 900 - 1300°C and a time of 0 - 5 hours kept at the ultimate temperature. As a matter of course, the carbonization operation may be omitted as the case may be.
The resultant carbonaceous material serves as a negative electrode material after pulverization and classification. The pulverization may be effected prior to or after the carbonization or after the firing.
Although the carbonaceous material as stated above is described, for example, in Japanese Patent Publication No.
53-31116, the optimization of the oxygen content results in a carbonaceous material which has a surface separation, doo2, at (002) plane of not less than 3.80 angstroms and no exothermic peak at 700°C or over when determined by differential thermal analysis (DTA) in a stream of air. 'The material is used as the negative electrode material.
The content of oxygen to be incorporated in petroleum pitch greatly influences the surface separation, doo2. at the (002) plane. For instance, when the axygen content in a precursor obtained by simple crosslinkage of petroleum pitch 2022~0~.
is not less than 10 wt%, the doo2 value can be not less than 3.70 angstroms. Accordingly, the oxygen content in the precursor should preferably be not less than 10 wt~. In practice, the content 3.s in the range of 10 - 20 wt%.
)Jspecially, s.l.nce tire doo2 value o:f not less t~kian 3.72 angstroms is favorable in view of the charging and discharging efficiency, the oxygen content should be appropr:late:Ly set; wh.i.:l.e taking tkre alcove :Lnto consa.deration.
In the pra<;t:Lce ofi' the :Lnvent.ton, phosphorus compounds are added at; the time oI' the carbonization by which the dop:Lng amount of lithium in the carbonaceous materla:l can be Increased.
P~xarnples or the plrosLylrorus compound include phosphorus oxides such as phosphorus trioxide, phosphorus tetraoxade, phosphorus pentaoxide and the :Like, oxo aca.ds oC phosphorus such as ortho-phosphor.Lc r.rc; l.d ( so-crx.L:Lcd plrovplror 1. c: rxc;.l.d ) , meta-phosphoric acid, polyplrosplroric ac:Ld rrrrc:l salts of these .
oxo ac:Lds. :I:n view of the ease in hand:Ling, phosphorus oxides and phosphoric acid are preferred.
In the pract.i.ce of the .Lnvention, the arrrouIlt of phosphorus compound to be added at the t9.me o:C the CarbUniZat.lon of organ:lc rnater.la:Ls shou:l.d be 0.2 - l.5 wt%, preferab:Ly U.5 - 7 wt~, based on the organic or carbonaceous material and tyre content of phospkrorus .Ln the carbonaceous material should be 0.2 ~- 5 wt~, if the amount oi' the phosphorus compound is less than the above range and the content of phospLtorus in the carbonaceous material is too small, the effect of increasing the dop:Lng amount of lithium cannot be apprecJ.ably expected. On the contrary, when t;he amount of the phosphorus compound is too large and the content of phosphorus in the carbonaceous mater:Lal becomes too large, tLre character:Lstics become poor with t;he possib:L:L:Lty of redtrc;:Lng a rate of c;arborraceous mater:l.a:I.
wh:Lch acturz:L:l.y lakes part a.n the dop.Lng of :L J.th:Lurn.
Where the carbonaceous material i.s used as a negative electrode of non-aqueous electrolyte cell, it is preferred that the mater:Lal used for pos:l.t.lve e:Lectrode should contain a satisfactory amount of L,J.. l~or this purpose, a composite metal ox:Lde oL' the genera:l_ formula, L,iMO~, (wherein M
represents at least one of Co and Na) or layer cornpotrnds contairr:Lng L:L are used. :Ln przrt.lcul.rtr, good c;lrFtrrzctor.l.stl.c;g are obta.Lrted where us:Lng 1.,.1.(;00.
The non-aqueous e:Lectro:l.yte c;eJ.l oL' tyre irtvent.l.on a.lrns at ach.Leving h:lgh capacity wherein the posJ.t.lve e:l.ec;erode shora:l.d corrtrz.l.n L.L irr amounts c;orrespondJ.ng to a charge and d.lsclrarge capaca. ty oC not :Less tlrtzn 250 rnnLr per g oI' t;he carhona<;eous nrtzterial far negat;ive e:Lectrode :Ln stat:Lonary condition (e.g. after about f:Lve repetitions of charging and d:lscharg.Lng). L1 should preferably be contained J.n amounts c;orrespond:Lng to a c;lrarge arid discharge capacity crL' not less ~~12~i~:~.
than 300 mAh and more preferably in amounts corresponding to a charge and discharge capacity of not less than 350 mAh.
It will be noted that Li is not necessarily supplied all from the positive electrode material on the condition that Li should be present in the cell system in amounts corresponding to a charge and discharge capacity of not less than 250 mAh per g of the carbonaceous material for negative electrode. The content of Li will be determined by measurement of the discharge capacil;y of cell.
The non-aqueous electrolyte is prepared by appropriately combining organic solvents and electrolytes, and these organic solvents and electrolytes may be ones ordinarily used in this type of cell.
Examples of the organic solvent include propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, 1,2-d3ethoxyethane, y -butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 7.,3-dioxorane, 4-methyl-1,3-dioxorane, diethyl ether, sulforane, methylsulforane, acetonitrile, propionylnitrile, anisole and the like.
Examples of the electrolyte include L1C10a, LiAsF~, LiPI~~, L9.Br4, LiB(C~IIS)~, CIIaSUaLI. CF3SOsLi, LiCl.. LiDr and the like.
When a phosphorus compound such as phosphoric acid is added at the time when organic materials are carbonized into ~o~z~~~.
carbonaceous material, an amount of doping lithium becomes great, with a great efficiency as expressed by de-doping amount/doping amount.
'the use of the carbonaceous mater:Lal having great capability of doping litha.urn as.a negative e:Lectrode of non-aqueous electrolyte cell results in an increasing charge and discharge capacity wlril.e suplaressing deter:Lorat:Lon accornpan.Led by repet.l. tl.on oI' chtrrgl.ng and d:Lsclrarga.ng operations.
L ~xarnples 'fhe present invention is described based on particu7.ar experirnental results.
Preliminary C~xperiment 1 lnit.tal.ly, a furan resin was used as an organic rnateria:l to check the lnf:Luence of phosphorus be.i.ng added.
I~ig. 1. :Ls a graph show.i.rrg tlrr vur.lrrtlorr of rr conta.rruous chargeable and dischargeab:l.e; furl[)ere-frour/g re.lat:lve to tire arnount of charged. phosphoric acid with respect to a ce:Ll wh.tcli makes use of a negat:Lve electrode whlc;h is obta.tned by C.I,r:l.ng a po:Lyfurl'ury:l. a:LcUllol res:Ln (rna:Le:lc anhydr:Lde catalyst) wlr.L:l.e add:lng phosphoric trcl.d. L~rorn th.Ls, :Lt wi:l:L
be seen thal; tire addit:ton or phosphoric ac:Ld upon .L':Lr:lng is very effective in increasing the charge and discharge capacity.
The added phosphorus cornpouncl was Ieft :Ln the resu:Lting 2~~~~~~
carbonaceous material as is shown in I'9.g. 2. :Lt will be noted that the amount of phosphorus in the carbonaceous rnaterial was quantitai;lvely determl.ned by an induct:lvely coupled plasma (1CP) spectrometry.
The fired product of the po:LyfurCuryl alcohol resin Itas not exotherrrtlc peak at 700°C or over when determined by I)TO
and has a surface separation, doom, at (002) plane of as :Large F,ts ,i.8 5 angstrorns. Wlrrn pltosphor.tc acl.cl was added dur:l.ng f:lrirrg o.f' the po:lyfurfuryl a:lcolro:l resin, l:Ltt;:le variation in the characteristics is observed as shown i.n Figs. 3 and 4. For :Lrrstance, the addition of 1.0 wt~ of phosphoric acl d entails an exotherrn:Ic: peak of F.rpproxarnately 680°C determined by D'fA and a cloo2 value of not :Less than 3.70 angstrorns.
By this, it was confirmed drat the add:l.Laon o(' Ltm phosphorus compound cl:l.d not Lmped<; t;tro <slntrrrc;Lcr.l.st.l<;s a.nherent to the r;arborrucoous mat;erlfrl..
Based on the results of the above Prelirn:lnary L:xarnp:l.e 7., a cell usl.ng a negative electrode made o!' a carbonaceous rnater:la:l which h:xd been obLalrred by !':l.r:tng a .Curan res:Ln to wlr:L<;h a phosphorus compound was added was assembled to evaluate its character-istlcs.
Example 1 500 g of furfuryl alcohol, 1 g of maleac anhyclrade and 200 g of pure water were rnlxed acrd refluxed on a hot water -lf-~~<~~~~~
bath for 2 hours to obtain a viscous polymer.
lifter removal of unreacted alcohol and residual water by vacuum distillation, 5 g of a 85~ phosphoric acid (II~PO") aqueous so,lut:Lon was added to 100 g of the polymer.
This was maintained for carboriazation :Ln a stream of nitrogen at 500°C for 5 hours, Followed by heating to 1200°C
and thermal treatment for 1 hour. The resultart carbon ace0us rnater:la:1 had the vl'o.l.:l.ow.l.ng c;hfzracterista.cs.
cloo2 = 3.82 rzngstrorns true density, p, - 1.55 g/crn3 exothermic peak by 1)T'A: 643°C
phosphorus content . aborzt 1.4 wt~
The thus obta.Lned carbonaceous mal;er.lal was used to const:ltute a cell as !'oll0ws.
The carbonaceous rnateria:L was lnj.t:La:Lly powdered by means of a rnorta .r anti c;.Lflss L C:led thr0uglr rz s.i.evc to c;o:l.:l.e;c: l;
part;ic:Les wLth a sloe o.L' ;l f)0 m-esh or be:l.ow.
1.00 rng of polyvi.nyl.idene f:l.uoride used as a b.lnder was added t0 :1 g of the classified carbonaceous mtzter-i.tz:L, and d.Lrnetlzy:l.Cormam-i.de was used Lo make a paste. i'ol:Lowed by app:l.lcrztaon to a sta:lnless steel. gauze and pressing at a pressure of 5 tor5s/crn?. The app.L.l.ed gauze was punt;hed Into a suitable form for use as a negative e:l.ectrode.
l1 positive electrode was made using LiN.io. 2t%oo, ~Oe in the fo:ll.owing manner.
_17_ 2Q~2~~~.
600 mg o.P graphite and 300 mg of polyethylene tetrafluoride were added to and mixed with 9.1 g of LiNio.2Coo.~02, after which 1 g of the mixture was placed in a mold and subjected to compression molding at a pressure of 2 tons/cm2 to obtain an electrode of a disk shape.
The thus obtained pos:Ltive and negata.ve electrodes were used and a'solution of 1 rnole/1 of LiGlO" in a mixed so:l.ution of propylene <;arbonate-da.rnethoxyet;hane (ratio by vo:Lurne o.(' 1 :.1. ) wFts used to rnake a co:In-shaped cell. for a charge and discharge test.
'fhe cell was arranged so that the arnount of. active substance was positive electrode » negative e:Lectrocle .C.rom the standpoint o:f e7.ectrochem:Lca1 equivalence, and the cell capacity was regulated at the negative electrode. In the charge and d.ischrzrge test, charging and discharg.lng were conducted at; a constant current; (0.5,3 rM/cm' ) .
'fhe ce:l.l wus clrargnd rtl; ,320, 350 r~n<l 380 rnAll/g (c;hu.rged rnA-hour per g of the carbonaceous material lterea.n etnd whenever it appears hereinafter) , wherein when a da.scharge cu l;-off vo:ltftge was set; ttt .1.5 V under wh.LCh a cycle test was effected, a good cyc7.e characterist:Ic was obtained in al:L the cases. :Crt I~ig. 5, the curve :L shows the characteristic obtalne<I by cltarg:lng at 380 mOII/g. The cell of this example d.ld not deterl.orate over 80 c:yc:les when charged at 380 rnllll/g.
2~~~:~~~.
Accordingly, it will be seen that the cell of ttr:Is example is chargeable or dlschargeable at a capacity which is higher than the theoretical in the case of graphite used as the~~negative electrode.
Iri Fig. 6, there i.s shown a discharge curve when the cell is charged at 380 mAIt/g (solid curve i.n the figure).
1'tre cell of th:Is example brad a charge and discharge e1't'lcJ.ency of 98.5% wltlr good results.
Cornparatlve ExtzmPle-1 After obtaining the polymer in the same manner as in Example 1, it was thermally treated without addition of any ptrosphorl.c acid to obtain a carbonaceous material.
'1'hls carbonaceous mater:Lal was used to make a cell in the same rnanner as Ln Example 1. The results of the cYrarge and discharge test are shown :ln I?:Ig. 5. f.rr F:Lg. 5, curve :L.i.
is a cycle charrrcterlsl;.i.c In tire rttsc; ol' <;lrrrrg,l.trg at 3130 rnAll/g, curve ll.l Ls a cycle clrarrr<;terlst.tc; .i.n. the case o~f chargl.rrg at 350 mAII/g and curve lv :Ls a cyc:l.e chara<;ter l.st.i.c :Ln the case of charging at 380 rnAl1/g.
:It; wl.:l.:l be seem that; a stab:l.e cycle characterast:l.c :Ls :L:LrnJ.ted only to the case where the c;hFrrged arnpere-tuour is approxlrnately 320 mAll/g.
1'he discharge curve when charged at 320 mAII/g is shown in F.ig. 6 (broken-line curvo l.n the f:Igure) . The charge ~znd d:Ischarge eff.lclency :Ls approxlrnatel.y 97%.
In order to confirm the effect of the case using other resin, a cell was s9.milarly assernbled using a novolac-type phenolic resin to evaluate its characteristics.
IJxample 2 g of pure water and 1 g of ethanol were added to 1.0 g of a novolac-type plrenollc resin powder (~PGA 4552 B, available from Gune:L Chern. Co. , Ltd. ) and wetted, after wh.Lc:h 5UU mg of a ti5°~ phosplu>rJ.c; acJ.d aqueous so:Lution was added and well mixed.
After keeping the mixture in a strearn of nitrogen at ' 500°C 'for 5 hours, it was heated up to 1200°C and thermal:Ly treated for 1 hour to obtain a carbonaceous rnater:lal. '.l'he thus obtained carbonaceous material had the following characteristics.
done = 3.75 angst;rums pure density, p , _ .1..60 g/em'' exothermic Iaeak by n~rA = (131°C
content of phosphorus: about 1.4 wt~
'fhe thUS UbtFl:lrred carbonaceous material Was used tU
make a ceJ.J. :Ln the carne manner as In hxamp:Le 1.
As a result of the charge and d:Lscharge test at dift'erent charged and discharged arrr.pere-hours, it was found that stable charging and dlsclnarging operations were ensured at a charged amount o:C not higher than 360 rnAII/g.
'.1'he cl.lsclrar-ge curve wherein charging was effected at 360 mAH/g is shown in Fig. 7 as a so:L:Ld line. In this case, the charge and discharge efficiency was 98%.
Comparative )xample 2 In the same manner as in );xample 2 except that phosphor..ic acid was not added to the novolac-type phenol resin powder, there was made a cell, followed by a charge and discharge cycle test at different charged amounts.
/1s a result, stable operat:Lons o:f charga.ng and d:Lscharg:Lng were :L.Lmi.ted to tire case where tire charged amount was at rnost ZJ.O rnAll/g.
'fhe discharge curve where charging was e.P:fected at 21.0 mAII/g 1s shown in Fig. 7 as a broken line. 'fhe charge and discharge efr'lcaency was approxirnatei.y 95%.
As wiJ..L become apparent from the above examples and comparat:Lve examples, carbonaceous materials ensuring a remarkably lrnproved charge and cL:Lsc;htzrge crzprzc;.l. ty ove;r known counterpfzrts can be cjbtn.Lnc;cL by tzdcJ:l.tion crI' hhosluhor.lc; ac;.Lcl.
)Jspec.La:l.J.y, tzs is descr.Lbed .Lrl Isxamp:l.r, 1., there cart be obtalrred a carbonaceous mater:Lal, depend.Lng on the type of star. tang rnater.ta:l., wltJ.ch htzS Fz c;barge and discharge capacity hJ.gher than tire theoretical. rzs expected by graphJ.te.
1'rellrnlnarv Lxperimerrt 2 Inltla:L:l.y, petro:Leurn pitctr (II/C atornac ratio of 0.6 -0.8) was oxidized to provide a carbon precursor having an oxygen content of 15.4 wt%. 'fo the precursor were added 2Q~z~~
various phosphorus compounds (ortho-phosphoric acid, phosphoric anhydride (phosphorus pentaoxide) and various phosphorates), followed by carbonization in a stream of nitrogen. at 500° for 5 hours.
flrer,eafter, the carbonized beads were powdered :Ln a mill arid charged into a crucible, fo:Llowed by faring in a stream of nitrogen at a heating rate of 5°C/minute at an ul.ta.rnate ternperrzture of 1.1.00°C for tx t:Lme oC :1. hour :for wh.i.ch the u:l.tLrnate temperature was rnaanta.ined.
/liter cooling, the product was powdered and classiried through a mesh to a size o-f not larger than 38,u m.
'these carbonaceous materials were eva:l.ttated t.rs:l.ng test cel:l.s.
t~or the fabr.i.cation of the test cell, the carbonaceous materials were, respectively, pre-heated, 7.mmediately prior to preparat.l.on o:f a rn:l.x for negrxt.Lve r:l.ec;trocle, irr Ft strertm of Ar under cond.l t.Lons of a hr~rtt.(rrg rrtte of about 30°C/rnlntrte, a ternperature crf 600°C and a lto:l.d:lng t.i.rne a.f 1 hour at the temperature. Thereafter, pol.yvanylidene f:lttor:lde used as tt binder was added to the material :Ln an amount of :1.0 wt~s based on the carbonaceous material, fol:lowed by rn:Lx.tng wl th d.lrnethy:l..('orrnarn.lde solvent and drying to obtain a negative electrode mix. Subsequently, 37 mg of the mix was molded along with a Ni mesh used as a current coll.ec;tor into a pellet with a diarneter o-f 15.5 rnrn, thereby 2~~,~~.~~.
obtaining a carbon electrode. The test cell had the following arrangement.
Cell arrangement coin-shaped cell (da.arneter of 20 mm, thickness oi' 2.5 rnm ) counter electrode : L, L metal separator: porous fil.rn (polypropy:l.ene) e:Lectro:l.yt;e: 1 rnoJ.e/:1. oC 1.,:1.C:L f)" ei:Lsso:Lved in a m:Lxed so:Lvent ( 1 : 1 by vo:Lurne) o.C propy.lene carbonate and me tlroxye thane current collector: copper foil The test cell with the above arrangernent was repeate<l.ly charged and discharged five t:Lrnes and .reached a stat:Lonary state, wlner.eupon a dJ.scharge capacity per g of the carbonaceous material const;it;tzting the carbon electrode was measured. 'fhe dop:lng of i.l.l;ha.um .i.n Llrc-~ crtrbon r,LecLroclo (c;harging: st;r.l,ctly c~peak.l.rrg, rza.l,horz~;h l;trr,, process of dop:l.ng Ln carbort in th:ls test method a.s not; charging but;
discharging, the doplng process is ca:L:l.ed clrarg:lng and tyre de-dopa.n6r process is caJ.led dasc;ttarging only for convenience' sake J.n v.Lew oC Lyre sa.Luat:Lon of actual cell) was performed at a current; density of 0. 53 rnll/crn~ by repetl.t.Lon of the cycle of one hour charging/two-hour L~reak until a balanced voltage reached 0 at the time of the break. 'fhe d:Lscharge (de-dopJ.ng of 7..Lthium -from the carbon) was performed at a ~fl2~1~~
current density of 0.53 mA/cm2 by repetition o.t' 1 hour discharging/two-hour break wherein a terminal voltage of 1.5 V was determined as a cut-off voltage.
As a result, all the phosphorus compounds could improve the discharge capacity of the carbonaceous material and the effect o'f the addition was in the order o-f anhydride>pllosphor:Lc aca.d>mUnobasi.c salt>ct:(. bas:(.c sa:l.t.
t~ig. 8 :Ls a clraractera.st.(.c v:Lew showing the re:latJ.orr between the arnount UI' phosphorus compounds (phosphorus pentaoxide and meta-phosphoric acid) added to the carbon precursor and the discharge capac:Lty. With meta-phosphor:tc acid, the discharge capacity becomes rnaxLmF.r:l. when tyre ac.tci is added in about 5 wt°~, over which it is kept almost constant. On the other brand, the capacity becomes rnaxirnal at 10 wt~ for phosphorus pentaoxide, UVer wha.<;h t;he discharge captlc:ity :Ls lowcrcd. The compara.son beLwc)rn meta-phospbror:Lc acid and phosphorus pentaox.l.de revea.l.s that the :Latter has a greater effect.
:!n '1'ab7.e 1., there is shown the cb:Lscharge capacity i11 cage Wblere typ:LCfll plrU9p11Urr1S CUtllpUllrldS are added.
Table 1 Phosphorus Compound Amount (wt~) Discharge Capacity (mnh~g) NaalIP03 ~ 5II~0 8.8 388 Na~HPOn ~ 2II20 6.7 431 P206 (dry) 5.8 494 I'~Oes + IIaO 5.8 466 II;iPOn 4. U 4;i(i When the car~tionaceaus material :Ls used as the; rrc~~at;ive e:lectracle of non-aqueous electrolyte cell, the surl'ac;e separat:larr (door) of the carbonaceous mater:la:L and the exotherm.i.c peak temperature ('1'p) apperxr:lng :ln the D'.I'A curve Ls considered to have floe c:Lose relata.an w:l tlr the cell.
characterlst.lcs.
Accordingly, how doa2 and '1'p are varied by the addition of a phosphorus campauncl and t;he relation het;ween Lhe _z5_ characteristics and the variations were determined.
As a result, it was found that doo2 = 3.73 angstroms when meta-phosphoric acid was added in 2 wt%, doo2 = 3.71 angstroms when added in 4 wt%, doo2 = 3.73 angstroms when added in 6 wt%, and doo2 = 3.71 angstroms when phosphorus pentaoxide was added in 6 wt%: The exotherm:Lc peak temperature in the D'1'A curve was changed as shown 9.n Fi.g. 9.
:l:n v:lew oC these resu:Lts, I;ire var:LtzL:i.ons o.C tire respec;t.Lve parameters caused by tire addition of the pltosphorus cornpourtds are not so prorraunced and the improvements of the character:lstics are not; da.rect:Ly proportional to the variat:Lons of the parameters, other factors being assumed to contribut;e t;o t;he irnprovements.
Moreover, the relation between the phospharus cornpounds bea.ng added and t;he content of phosphorus left in the carbonaceous rnatesra.a:l. was deterrn:l.ned. 'I'ltc r<;yl,dua.L rtrnourtt of phosphorus was nreasurc;d Ln rite same manner fzs a.n Prelim:Lnary Cxperirnent 1. The resu:l.ts are shown in P:Lg. 10.
As the amount of the phosphorus compound .Lnc.reases, the content of phosphorus left :(.n the carbona<;eons materia:L
eventua:L:l.y increases, with Lhe tendency that the res:Ldua:L
arnount; of phosphorus :Ls saturated aL approximately 3 wt%.
According:ly, the amount of phosphorus left in carbonaceous mater:Lal. should preferably be O.L - 3 wt%, more preferab:l.y U.5 - 5 wt%.
2~~~~.~~.
Based on the results of the above Preliminary Experiment, a carbonaceous material which had been fired by adding a phosphorus to a carbon precursor obtained by introducing an oxygen-containing functional group into petroleum p:itch was used to assemble a non-aqueous secondary cell for determination of its characteristics.
Example 3 I1 petroleurn p:1 tch whose I1/C atomic rat:Lo was appropr:l.ate7.y se7.ected from a range of U.6 - U.8 was broken into pieces and sub,~ected to oxidation treatment in a stream of oxygen to obtain a carbon precursor. The carbon precursor had a quinolirre insoluble content (centr9.fugal method by J1S: K2425-1983) o.f 8U% and an oxygen content (by organic element analysis) of 15.4 wt~.
6 wt% of phosphorus pentaoxide (P208 was added to tire carbon precursor, wha.ch was carborr:Lzed .Ln rr sl;ream oI' nitrogen nt 5UU° I'or 5 hours, i'o.L:l.owc~d by heFrt:Irrg Lo li.UU°C
for 1 hour.
The resultant carbonaceous mal;eria:l. was used to constitute a ce:Ll as .fo:L7.ows.
The carbonaceous rnaterial was initial.:ly powdered by means of a rnortar and classified through a s:Leve to collect particles with a size of 39U mesh or below.
lU0 mg of polyvinylidene fluoride used as a binder was added to 1. g of the carbonic;eons mat-er:lal, and _27-~02219~.
dimethylformamide was used to make a paste, followed by application to a stainless steel gauze, drying and pressing at a pressure of 5 tons/cm2. The applied gauze was punched into a suitable form for use as a negative electrode. The net weight of the carbonaceous material was 32.4 mg.
A positive electrode was made using LiNio.2Coo:e02 as art act9.ve substance. 6 g of graphite and 3 g o.C
polyethylene teLraf:Luor:Lde were added to arid we:l:L mixed whit 91 g of L:LN:Lo. aCoo. e0a, after which 1 g of the mixture was Placed in a mold and subjected to compression molding at a pressure of 2 tons/cm2 to obtain an electrode of a disk shape.
1'he thus obtained positive and negative electrodes were used. A solution of 1 rnole/:L of LiC104 in a mixed solution of propylene carbonate-1,2-dimethoxyethane (ratio by volume of 1:1) and a poiypropy:lene non-woven frtbr:l.c wc;ro usctd l,o make a coin-shaped ce:Ll. 'l'ltc cel:L rnacln use of the actl.ve substance :Ln such an amount that positive electrode»negat.Lve electrode from the standpoirtL of the e:Lectrochemica7. eduiva:l.ence as regulated by the negat:Lve e:Lectrode.
Comparative Example 3 In the same manner as in Exarnple 3 except that phosphorus pentaoxlde was not added upon carbonization of the carbon precursor, there was obtained a coin-shaped cell.
With regard to Example 3 and Comparative Example 3, discharge curves were drawn. 'fhe results are shown i.n Fig.
11. In the figure, the solid line indicates the discharge curve of Example 3 and the broken line ind.tcates the discharge curve of Comparat9.ve Example 3.
From F:Ig. 11, :Lt wall be seen that the cell using the fired product to wh:lch the phosphorus compound as added 1s s:IgnJ, f:l.c;anl;:ly better, wi th respec; t; to t;lre capac:l ty.
'fhe celi.s of Exarnp:le 3 tznd Comparat:lve Exarnple 3 were sub,Jected to deterrn:kned of a cycle characteristic. In the charge and discharge test, the current density was 0.53 mA/cm2 for. both charge and discharge under a consl;ant;
current and the cut-off voltage of the d:lsclrarge was set at 1..5 V. The resu7_ts are shown in Fig. J.2.
:l:n rig. 12, lane a Ls a cycle character:lstic a.n case, where the cell. ofi Exarnp:l.e ;; wrzy c;hrzrgcck rzt 3(i0 rnAlr/g, l..l.ne b is a cyc;i.e. clrFrrnc;tnr.l.~rt.l <; Ln crzyr whcrc; t;lre c;c l .l. of Comparat:l.ve Cxarnple 3 was charged at 360 rnAlr/g and :Line c; a.s a cycle c;harac;ter:l.sti.c in case where the cell. of Comparative Example 3 was charged tzt 320 mAh/g.
With the ce:il of Example 3, t exh:Lbits a good cycle character:Lstic when charged at 360 rnAh/g. In Comparative Example 3, the life 1s very short. When the cell of Cornparati.ve Example 3 was charged at 320 m/1h/g, a good cycle charrzcter:i.st:lc is obt;ai.ned lrut Che dl.scharge capac:lty is small.
Specific examples of the invention are described, which should not be construed as limit:Lng the invention thereto.
Various varaat.ions rnay be poss:Lb:Le wl.thout departing .Prom the scope of the invent:Lon.
As will be apparent from the foregoing, the carbonaceous rnater:Lal. of i;he :l.nventa.on contrz:Lns pkrosphorus rznd the present :l.nvention can provl.de a carbonaceous mater:lal capab:Le of dop:Lng :Lathiurn in large amounts.
According to the method of the invent.ton, there ca.n be prepared a carbonaceous material tray:lng good c;harrzcter.lstics by a sample procedure and espec:La:Lly a carbonaceous mater:La:1 which ttas great capability of doping lithium and a good charge and dlsclzarge effi.rl.ency (de-doping/doping amounts).
In the non-aqueous el.ect;ro:l.yte c;e:l.:l. of the .Lnventl.c~rt, the carbonaceous rnater l.rza Irrzv.l.ry grE;rtl; caprztr:L:l. i ty oC
dop.l.ng litlrl.um and a good charge and cl:Lscharge el'C:lc.lency .Ls used as a negative electrode whereby one can rea:L:lze a charge and d:Lscharge c;apac.Lty wir.lc;h .l.s lt.l.gher than tkze theoretical as :In aloe case us.lng graphite rzs a negative electrode. 'thus, .Lt :ks poss.Lbl.e to provide the ce:l.:l. havl.ng excellent cycle characteristics and an excellent charge and discharge efficiency.
Claims (8)
1. A carbonaceous material having an interlayer spacing, doo2, of not less than 3.70 angstroms and a true density of less than 1.70 g/cm~, having no exothermic peak at not less than 700°C as measured by a diffraction thermal analysis in air stream, and containing from 0.2 to 5.0 weight % of phosphorus.
2. A carbonaceous material according to Claim 1, wherein said carbonaceous material is obtained by carbonizing an organic material.
3. A carbonaceous material according to Claim 2, wherein said organic material is a furan resin.
4. A carbonaceous material according to claim 2, wherein said organic material is a petroleum pitch having a H/C atomic ratio between 0.6 and 0.8 and containing functional groups containing oxygen.
5. A non-aqueous electrolyte cell comprising an anode of a carbonaceous material having an an interlayer spacing, dooz, of not less than 3.70 angstroms and a true density of less than 1.70 g/cm~, having no exothermic peak at not less than 700°C as measured by a diffraction thermal analysis in air stream, and containing from 0.2 to 5.0 weight % of phosphorus, a cathode containing Li, and a non-aqueous electrolyte.
6. A non-aqueous electrolyte cell according to Claim 5, wherein said cathode contains Li in an amount of corresponding to the charge/discharge capacity of not less than 350 mAll per gram of said carbonaceous material.
7. A non-aqueous electrolyte cell according to Claim 5, wherein said cathode contains Li in an amount corresponding to the charge/discharge capacity of not less than 350 mAH
per gram of said carbonaceous material.
per gram of said carbonaceous material.
8. A non-aqueous electrolyte cell according to Claim 5, wherein said cathode contains a cathode active material of the formula, LiMO2, wherein M stands for at least one of Co and NI.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP197596/89 | 1989-07-29 | ||
| JP19759689 | 1989-07-29 | ||
| JP048184/90 | 1990-02-28 | ||
| JP02048184A JP3060474B2 (en) | 1989-07-29 | 1990-02-28 | Negative electrode for battery, method for producing the same, and nonaqueous electrolyte battery using the same |
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| Publication Number | Publication Date |
|---|---|
| CA2022191A1 CA2022191A1 (en) | 1991-01-30 |
| CA2022191C true CA2022191C (en) | 2000-12-12 |
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|---|---|---|---|
| CA002022191A Expired - Lifetime CA2022191C (en) | 1989-07-29 | 1990-07-27 | Carbonaceous material and a non-aqueous electrolyte cell using the same |
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| Country | Link |
|---|---|
| US (1) | US5093216A (en) |
| EP (1) | EP0418514B1 (en) |
| AT (1) | ATE105975T1 (en) |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9070933B2 (en) | 2010-11-12 | 2015-06-30 | Nippon Steel Chemical Co., Ltd. | Negative electrode active material of lithium secondary battery, secondary battery using the same, method for manufacturing the same |
Families Citing this family (53)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2055305C (en) * | 1990-11-17 | 2002-02-19 | Naoyuki Sugeno | Nonaqueous electrolyte secondary battery |
| US5294498A (en) * | 1991-03-02 | 1994-03-15 | Sony Corporation | Anode material, method for producing it and non-aqueous electrolyte cell employing such anode materials |
| JP3196226B2 (en) * | 1991-03-13 | 2001-08-06 | ソニー株式会社 | Non-aqueous electrolyte secondary battery |
| JP3282189B2 (en) * | 1991-07-31 | 2002-05-13 | ソニー株式会社 | Non-aqueous electrolyte secondary battery |
| JPH05101818A (en) * | 1991-08-07 | 1993-04-23 | Mitsubishi Gas Chem Co Inc | Carbon molded body for negative electrode and lithium secondary battery |
| CA2083001C (en) * | 1991-12-17 | 1996-12-17 | Yuzuru Takahashi | Lithium secondary battery using a non-aqueous solvent |
| DE69311170T2 (en) * | 1992-03-18 | 1997-12-04 | Matsushita Electric Ind Co Ltd | Negative electrode for a storage battery with a non-aqueous electrolyte and process for its production |
| US5192629A (en) * | 1992-04-21 | 1993-03-09 | Bell Communications Research, Inc. | High-voltage-stable electrolytes for Li1+x Mn2 O4 /carbon secondary batteries |
| US5512393A (en) * | 1992-07-06 | 1996-04-30 | Nikkiso Company Limited | Vapor-grown and graphitized carbon fibers process for preparing same molded members thereof and composite members thereof |
| US5677084A (en) * | 1992-12-25 | 1997-10-14 | Toray Industries, Inc. | Electrode and secondary battery using the same |
| US5358802A (en) * | 1993-04-01 | 1994-10-25 | Regents Of The University Of California | Doping of carbon foams for use in energy storage devices |
| JPH0737577A (en) * | 1993-07-26 | 1995-02-07 | Mitsubishi Gas Chem Co Inc | Improved non-aqueous solvent lithium secondary battery |
| US5536597A (en) * | 1993-12-17 | 1996-07-16 | Mitsubishi Gas Chemical Company | Lithium secondary battery employing a non-aqueous electrolyte |
| JP3082557B2 (en) * | 1994-02-10 | 2000-08-28 | 松下電器産業株式会社 | Manufacturing method of non-aqueous electrolyte secondary battery |
| AU1147597A (en) * | 1995-12-07 | 1997-06-27 | Sandia Corporation | Methods of preparation of carbon materials for use as electrodes in rechargeable batteries |
| US5647963A (en) * | 1995-12-20 | 1997-07-15 | Motorola, Inc. | Electrode materials for electrochemical cells and method of making same |
| JP3436033B2 (en) * | 1996-12-27 | 2003-08-11 | ソニー株式会社 | Non-aqueous electrolyte secondary battery |
| CN1078747C (en) * | 1997-07-17 | 2002-01-30 | 中国科学院化学研究所 | Carbon negative-pole material for secondary lithium battery and its preparation |
| EP0921582B1 (en) * | 1997-11-19 | 2003-02-12 | Mitsubishi Gas Chemical Company, Inc. | A carbonaceous material for use as an anode of a lithium secondary battery and method of preparation |
| TW583153B (en) * | 2001-09-25 | 2004-04-11 | Showa Denko Kk | Carbon material, production method and use thereof |
| KR100751772B1 (en) * | 2003-06-05 | 2007-08-23 | 쇼와 덴코 가부시키가이샤 | Carbon material for battery electrode and production method and use thereof |
| JP5153055B2 (en) * | 2003-10-31 | 2013-02-27 | 昭和電工株式会社 | Carbon material for lithium secondary battery electrode, manufacturing method thereof, electrode paste, electrode for lithium secondary battery, and lithium secondary battery |
| KR101496934B1 (en) | 2006-11-15 | 2015-03-03 | 유니버시티 오브 워싱톤 스루 이츠 센터 포 커머셜리제이션 | electric double layer capacitance device |
| US20100141211A1 (en) * | 2008-11-04 | 2010-06-10 | Rachid Yazami | Hybrid electrochemical generator with a soluble anode |
| JP5662698B2 (en) | 2009-05-15 | 2015-02-04 | 新日鉄住金化学株式会社 | Negative electrode active material for lithium secondary battery and in-vehicle lithium secondary battery using the same |
| CN105226284B (en) | 2009-07-01 | 2017-11-28 | 巴斯夫欧洲公司 | Ultrapure synthetic carbon materials |
| US20110171119A1 (en) * | 2009-12-14 | 2011-07-14 | Rachid Yazami | Hydrogen storage and/or generation |
| WO2012045002A1 (en) | 2010-09-30 | 2012-04-05 | Energ2 Technologies, Inc. | Enhanced packing of energy storage particles |
| US20120262127A1 (en) | 2011-04-15 | 2012-10-18 | Energ2 Technologies, Inc. | Flow ultracapacitor |
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| WO2013120011A1 (en) | 2012-02-09 | 2013-08-15 | Energ2 Technologies, Inc. | Preparation of polymeric resins and carbon materials |
| US20150263347A1 (en) | 2012-08-30 | 2015-09-17 | Kureha Corporation | Carbon material for nonaqueous electrolyte secondary battery and method for manufacturing same, and negative electrode using carbon material and nonaqueous electrolyte secondary battery |
| WO2014129487A1 (en) * | 2013-02-19 | 2014-08-28 | 株式会社クレハ | Carbon material for non-aqueous electrolyte secondary battery negative electrode |
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| US20160344030A1 (en) * | 2013-06-12 | 2016-11-24 | Energ2 Technologies, Inc. | High capacity hard carbon materials comprising efficiency enhancers |
| US9455447B2 (en) * | 2013-09-26 | 2016-09-27 | Eaglepicher Technologies, Llc | Lithium-sulfur battery and methods of preventing insoluble solid lithium-polysulfide deposition |
| US10195583B2 (en) | 2013-11-05 | 2019-02-05 | Group 14 Technologies, Inc. | Carbon-based compositions with highly efficient volumetric gas sorption |
| KR102663138B1 (en) | 2014-03-14 | 2024-05-03 | 그룹14 테크놀로지스, 인코포레이티드 | Novel methods for sol-gel polymerization in absence of solvent and creation of tunable carbon structure from same |
| KR20170032440A (en) * | 2014-08-29 | 2017-03-22 | 스미또모 베이크라이트 가부시키가이샤 | Secondary battery negative electrode resin composition, method for producing secondary battery negative electrode carbon material, secondary battery negative electrode carbon material, modified phenolic hydroxyl group for use in secondary battery negative electrode, secondary battery negative electrode active material, secondary battery negative electrode, and secondary battery |
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| CN119419246A (en) | 2015-08-28 | 2025-02-11 | 14集团技术公司 | New materials with extremely durable lithium intercalation and methods for making them |
| CN105293467A (en) * | 2015-10-21 | 2016-02-03 | 山东玉皇新能源科技有限公司 | Phenolic resin/coal tar pitch composite-base modified hard carbon negative electrode material and preparation method and application thereof |
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| CN116457309B (en) | 2020-09-30 | 2025-02-14 | 14集团技术公司 | Passivation method to control oxygen content and reactivity of silicon-carbon composites |
| CN114824165B (en) * | 2022-06-30 | 2022-10-14 | 宁德新能源科技有限公司 | Negative electrode plate, electrochemical device and electronic equipment |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3207687A (en) * | 1963-09-25 | 1965-09-21 | Minnesota Mining & Mfg | Preparation of thermosetting resinous material |
| US4702977A (en) * | 1985-04-30 | 1987-10-27 | Toshiba Battery Co., Ltd. | Secondary battery using non-aqueous solvent |
| US4737423A (en) * | 1985-12-30 | 1988-04-12 | Allied Corporation | Cathode active material for metal of CFX battery |
| CA1296766C (en) * | 1986-05-13 | 1992-03-03 | Yuzuru Takahashi | Secondary battery |
| US4945014A (en) * | 1988-02-10 | 1990-07-31 | Mitsubishi Petrochemical Co., Ltd. | Secondary battery |
| JP2674793B2 (en) * | 1988-08-31 | 1997-11-12 | ソニー 株式会社 | Non-aqueous electrolyte battery |
-
1990
- 1990-07-26 DE DE69008978T patent/DE69008978T2/en not_active Expired - Lifetime
- 1990-07-26 EP EP90114383A patent/EP0418514B1/en not_active Expired - Lifetime
- 1990-07-26 AT AT90114383T patent/ATE105975T1/en not_active IP Right Cessation
- 1990-07-27 US US07/558,470 patent/US5093216A/en not_active Expired - Lifetime
- 1990-07-27 CA CA002022191A patent/CA2022191C/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9070933B2 (en) | 2010-11-12 | 2015-06-30 | Nippon Steel Chemical Co., Ltd. | Negative electrode active material of lithium secondary battery, secondary battery using the same, method for manufacturing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0418514A1 (en) | 1991-03-27 |
| ATE105975T1 (en) | 1994-06-15 |
| US5093216A (en) | 1992-03-03 |
| DE69008978T2 (en) | 1994-12-01 |
| EP0418514B1 (en) | 1994-05-18 |
| DE69008978D1 (en) | 1994-06-23 |
| CA2022191A1 (en) | 1991-01-30 |
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