JP5268042B2 - Method for producing positive electrode active material and non-aqueous electrolyte battery using the same - Google Patents
Method for producing positive electrode active material and non-aqueous electrolyte battery using the same Download PDFInfo
- Publication number
- JP5268042B2 JP5268042B2 JP2006317795A JP2006317795A JP5268042B2 JP 5268042 B2 JP5268042 B2 JP 5268042B2 JP 2006317795 A JP2006317795 A JP 2006317795A JP 2006317795 A JP2006317795 A JP 2006317795A JP 5268042 B2 JP5268042 B2 JP 5268042B2
- Authority
- JP
- Japan
- Prior art keywords
- positive electrode
- active material
- electrode active
- doped
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 68
- 239000011255 nonaqueous electrolyte Substances 0.000 title claims abstract description 29
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 22
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 53
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 45
- ILXAVRFGLBYNEJ-UHFFFAOYSA-K lithium;manganese(2+);phosphate Chemical compound [Li+].[Mn+2].[O-]P([O-])([O-])=O ILXAVRFGLBYNEJ-UHFFFAOYSA-K 0.000 claims abstract description 44
- 229910015645 LiMn Inorganic materials 0.000 claims abstract description 28
- 229910052751 metal Inorganic materials 0.000 claims abstract description 24
- 239000002184 metal Substances 0.000 claims abstract description 24
- 238000000034 method Methods 0.000 claims abstract description 19
- 239000000203 mixture Substances 0.000 claims abstract description 11
- 239000012298 atmosphere Substances 0.000 claims abstract description 10
- 239000011261 inert gas Substances 0.000 claims abstract description 8
- 239000002245 particle Substances 0.000 claims description 40
- 229910052749 magnesium Inorganic materials 0.000 claims description 8
- 239000006230 acetylene black Substances 0.000 claims description 6
- 229910052719 titanium Inorganic materials 0.000 claims description 6
- 239000007833 carbon precursor Substances 0.000 claims description 5
- 238000002156 mixing Methods 0.000 abstract description 8
- 230000008569 process Effects 0.000 abstract description 7
- 239000011777 magnesium Substances 0.000 description 38
- 238000010438 heat treatment Methods 0.000 description 26
- 229910052744 lithium Inorganic materials 0.000 description 22
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 21
- 239000010936 titanium Substances 0.000 description 20
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 14
- 239000011572 manganese Substances 0.000 description 13
- 239000007773 negative electrode material Substances 0.000 description 13
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 10
- 150000001875 compounds Chemical class 0.000 description 10
- 239000010450 olivine Substances 0.000 description 10
- 229910052609 olivine Inorganic materials 0.000 description 10
- 239000000463 material Substances 0.000 description 9
- -1 organic acid salt Chemical class 0.000 description 9
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 8
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 7
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 6
- 239000002033 PVDF binder Substances 0.000 description 6
- 239000003792 electrolyte Substances 0.000 description 6
- 229910001416 lithium ion Inorganic materials 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 239000002002 slurry Substances 0.000 description 6
- DLYUQMMRRRQYAE-UHFFFAOYSA-N tetraphosphorus decaoxide Chemical compound O1P(O2)(=O)OP3(=O)OP1(=O)OP2(=O)O3 DLYUQMMRRRQYAE-UHFFFAOYSA-N 0.000 description 6
- 239000011230 binding agent Substances 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 239000011888 foil Substances 0.000 description 5
- 239000012535 impurity Substances 0.000 description 5
- 229910052742 iron Inorganic materials 0.000 description 5
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 5
- 239000004810 polytetrafluoroethylene Substances 0.000 description 5
- 239000002904 solvent Substances 0.000 description 5
- 229910000319 transition metal phosphate Inorganic materials 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 4
- 229910052783 alkali metal Inorganic materials 0.000 description 4
- 150000001340 alkali metals Chemical class 0.000 description 4
- 239000007864 aqueous solution Substances 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 4
- 238000000576 coating method Methods 0.000 description 4
- 239000004020 conductor Substances 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 4
- 229910052808 lithium carbonate Inorganic materials 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 4
- 229920005569 poly(vinylidene fluoride-co-hexafluoropropylene) Polymers 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 239000003566 sealing material Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- WEVYAHXRMPXWCK-UHFFFAOYSA-N Acetonitrile Chemical compound CC#N WEVYAHXRMPXWCK-UHFFFAOYSA-N 0.000 description 3
- 229910013870 LiPF 6 Inorganic materials 0.000 description 3
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007772 electrode material Substances 0.000 description 3
- 230000006872 improvement Effects 0.000 description 3
- 239000011244 liquid electrolyte Substances 0.000 description 3
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 3
- 229910003002 lithium salt Inorganic materials 0.000 description 3
- 159000000002 lithium salts Chemical class 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 3
- 239000008188 pellet Substances 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000007784 solid electrolyte Substances 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- MYRTYDVEIRVNKP-UHFFFAOYSA-N 1,2-Divinylbenzene Chemical compound C=CC1=CC=CC=C1C=C MYRTYDVEIRVNKP-UHFFFAOYSA-N 0.000 description 2
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 description 2
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 2
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 2
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- 229910013063 LiBF 4 Inorganic materials 0.000 description 2
- 229910013684 LiClO 4 Inorganic materials 0.000 description 2
- 229910011281 LiCoPO 4 Inorganic materials 0.000 description 2
- 229910015643 LiMn 2 O 4 Inorganic materials 0.000 description 2
- 229910013086 LiNiPO Inorganic materials 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 239000011149 active material Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 239000003125 aqueous solvent Substances 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 239000012300 argon atmosphere Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 150000001768 cations Chemical class 0.000 description 2
- 150000005678 chain carbonates Chemical class 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 150000005676 cyclic carbonates Chemical class 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- VUPKGFBOKBGHFZ-UHFFFAOYSA-N dipropyl carbonate Chemical compound CCCOC(=O)OCCC VUPKGFBOKBGHFZ-UHFFFAOYSA-N 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000000445 field-emission scanning electron microscopy Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 239000011245 gel electrolyte Substances 0.000 description 2
- AMWRITDGCCNYAT-UHFFFAOYSA-L hydroxy(oxo)manganese;manganese Chemical compound [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- HSZCZNFXUDYRKD-UHFFFAOYSA-M lithium iodide Chemical compound [Li+].[I-] HSZCZNFXUDYRKD-UHFFFAOYSA-M 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000002105 nanoparticle Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 229920000620 organic polymer Polymers 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- VXUYXOFXAQZZMF-UHFFFAOYSA-N titanium(IV) isopropoxide Chemical compound CC(C)O[Ti](OC(C)C)(OC(C)C)OC(C)C VXUYXOFXAQZZMF-UHFFFAOYSA-N 0.000 description 2
- 229910052723 transition metal Inorganic materials 0.000 description 2
- 150000003624 transition metals Chemical class 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- BQCIDUSAKPWEOX-UHFFFAOYSA-N 1,1-Difluoroethene Chemical compound FC(F)=C BQCIDUSAKPWEOX-UHFFFAOYSA-N 0.000 description 1
- ZZXUZKXVROWEIF-UHFFFAOYSA-N 1,2-butylene carbonate Chemical compound CCC1COC(=O)O1 ZZXUZKXVROWEIF-UHFFFAOYSA-N 0.000 description 1
- LZDKZFUFMNSQCJ-UHFFFAOYSA-N 1,2-diethoxyethane Chemical compound CCOCCOCC LZDKZFUFMNSQCJ-UHFFFAOYSA-N 0.000 description 1
- WNXJIVFYUVYPPR-UHFFFAOYSA-N 1,3-dioxolane Chemical compound C1COCO1 WNXJIVFYUVYPPR-UHFFFAOYSA-N 0.000 description 1
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- JWUJQDFVADABEY-UHFFFAOYSA-N 2-methyltetrahydrofuran Chemical compound CC1CCCO1 JWUJQDFVADABEY-UHFFFAOYSA-N 0.000 description 1
- RVDLHGSZWAELAU-UHFFFAOYSA-N 5-tert-butylthiophene-2-carbonyl chloride Chemical compound CC(C)(C)C1=CC=C(C(Cl)=O)S1 RVDLHGSZWAELAU-UHFFFAOYSA-N 0.000 description 1
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- JGFBQFKZKSSODQ-UHFFFAOYSA-N Isothiocyanatocyclopropane Chemical compound S=C=NC1CC1 JGFBQFKZKSSODQ-UHFFFAOYSA-N 0.000 description 1
- 229910000733 Li alloy Inorganic materials 0.000 description 1
- 229910012425 Li3Fe2 (PO4)3 Inorganic materials 0.000 description 1
- 229910015015 LiAsF 6 Inorganic materials 0.000 description 1
- 229910013372 LiC 4 Inorganic materials 0.000 description 1
- 229910012851 LiCoO 2 Inorganic materials 0.000 description 1
- 229910011500 LiCuPO Inorganic materials 0.000 description 1
- 229910013275 LiMPO Inorganic materials 0.000 description 1
- 229910015355 LiMgPO Inorganic materials 0.000 description 1
- 229910013290 LiNiO 2 Inorganic materials 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 229910021380 Manganese Chloride Inorganic materials 0.000 description 1
- GLFNIEUTAYBVOC-UHFFFAOYSA-L Manganese chloride Chemical compound Cl[Mn]Cl GLFNIEUTAYBVOC-UHFFFAOYSA-L 0.000 description 1
- RJUFJBKOKNCXHH-UHFFFAOYSA-N Methyl propionate Chemical compound CCC(=O)OC RJUFJBKOKNCXHH-UHFFFAOYSA-N 0.000 description 1
- 239000002228 NASICON Substances 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- LFVGISIMTYGQHF-UHFFFAOYSA-N ammonium dihydrogen phosphate Chemical compound [NH4+].OP(O)([O-])=O LFVGISIMTYGQHF-UHFFFAOYSA-N 0.000 description 1
- 229910000387 ammonium dihydrogen phosphate Inorganic materials 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 230000003466 anti-cipated effect Effects 0.000 description 1
- PWLNAUNEAKQYLH-UHFFFAOYSA-N butyric acid octyl ester Natural products CCCCCCCCOC(=O)CCC PWLNAUNEAKQYLH-UHFFFAOYSA-N 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 235000019241 carbon black Nutrition 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000004917 carbon fiber Substances 0.000 description 1
- 239000011203 carbon fibre reinforced carbon Substances 0.000 description 1
- 229910021393 carbon nanotube Inorganic materials 0.000 description 1
- 239000002041 carbon nanotube Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 235000010980 cellulose Nutrition 0.000 description 1
- 229920001940 conductive polymer Polymers 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 239000011889 copper foil Substances 0.000 description 1
- 239000007799 cork Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- MNNHAPBLZZVQHP-UHFFFAOYSA-N diammonium hydrogen phosphate Chemical compound [NH4+].[NH4+].OP([O-])([O-])=O MNNHAPBLZZVQHP-UHFFFAOYSA-N 0.000 description 1
- 229910000388 diammonium phosphate Inorganic materials 0.000 description 1
- 235000019838 diammonium phosphate Nutrition 0.000 description 1
- YNQRWVCLAIUHHI-UHFFFAOYSA-L dilithium;oxalate Chemical compound [Li+].[Li+].[O-]C(=O)C([O-])=O YNQRWVCLAIUHHI-UHFFFAOYSA-L 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 238000007580 dry-mixing Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 235000021552 granulated sugar Nutrition 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 239000008240 homogeneous mixture Substances 0.000 description 1
- 229910003480 inorganic solid Inorganic materials 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 150000002596 lactones Chemical class 0.000 description 1
- XIXADJRWDQXREU-UHFFFAOYSA-M lithium acetate Chemical compound [Li+].CC([O-])=O XIXADJRWDQXREU-UHFFFAOYSA-M 0.000 description 1
- 239000001989 lithium alloy Substances 0.000 description 1
- 150000002642 lithium compounds Chemical class 0.000 description 1
- IDBFBDSKYCUNPW-UHFFFAOYSA-N lithium nitride Chemical compound [Li]N([Li])[Li] IDBFBDSKYCUNPW-UHFFFAOYSA-N 0.000 description 1
- 229940071125 manganese acetate Drugs 0.000 description 1
- 235000006748 manganese carbonate Nutrition 0.000 description 1
- 239000011656 manganese carbonate Substances 0.000 description 1
- 229940093474 manganese carbonate Drugs 0.000 description 1
- 235000002867 manganese chloride Nutrition 0.000 description 1
- 239000011565 manganese chloride Substances 0.000 description 1
- 229940099607 manganese chloride Drugs 0.000 description 1
- IPJKJLXEVHOKSE-UHFFFAOYSA-L manganese dihydroxide Chemical compound [OH-].[OH-].[Mn+2] IPJKJLXEVHOKSE-UHFFFAOYSA-L 0.000 description 1
- UOGMEBQRZBEZQT-UHFFFAOYSA-L manganese(2+);diacetate Chemical compound [Mn+2].CC([O-])=O.CC([O-])=O UOGMEBQRZBEZQT-UHFFFAOYSA-L 0.000 description 1
- RGVLTEMOWXGQOS-UHFFFAOYSA-L manganese(2+);oxalate Chemical compound [Mn+2].[O-]C(=O)C([O-])=O RGVLTEMOWXGQOS-UHFFFAOYSA-L 0.000 description 1
- 229910000016 manganese(II) carbonate Inorganic materials 0.000 description 1
- XMWCXZJXESXBBY-UHFFFAOYSA-L manganese(ii) carbonate Chemical compound [Mn+2].[O-]C([O-])=O XMWCXZJXESXBBY-UHFFFAOYSA-L 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000003701 mechanical milling Methods 0.000 description 1
- 238000007578 melt-quenching technique Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000002931 mesocarbon microbead Substances 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 229940017219 methyl propionate Drugs 0.000 description 1
- 239000012046 mixed solvent Substances 0.000 description 1
- 235000019837 monoammonium phosphate Nutrition 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- UUIQMZJEGPQKFD-UHFFFAOYSA-N n-butyric acid methyl ester Natural products CCCC(=O)OC UUIQMZJEGPQKFD-UHFFFAOYSA-N 0.000 description 1
- 229910052754 neon Inorganic materials 0.000 description 1
- GKAOGPIIYCISHV-UHFFFAOYSA-N neon atom Chemical compound [Ne] GKAOGPIIYCISHV-UHFFFAOYSA-N 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- LYGJENNIWJXYER-UHFFFAOYSA-N nitromethane Chemical compound C[N+]([O-])=O LYGJENNIWJXYER-UHFFFAOYSA-N 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000005486 organic electrolyte Substances 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 235000011007 phosphoric acid Nutrition 0.000 description 1
- 239000006253 pitch coke Substances 0.000 description 1
- 229920000058 polyacrylate Polymers 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 239000005518 polymer electrolyte Substances 0.000 description 1
- 229920006254 polymer film Polymers 0.000 description 1
- 229920000193 polymethacrylate Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- FVSKHRXBFJPNKK-UHFFFAOYSA-N propionitrile Chemical compound CCC#N FVSKHRXBFJPNKK-UHFFFAOYSA-N 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- HXJUTPCZVOIRIF-UHFFFAOYSA-N sulfolane Chemical compound O=S1(=O)CCCC1 HXJUTPCZVOIRIF-UHFFFAOYSA-N 0.000 description 1
- 150000003457 sulfones Chemical class 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 238000004448 titration Methods 0.000 description 1
- 229910000314 transition metal oxide Inorganic materials 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- 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
Landscapes
- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
Description
本発明は、非水電解質電池用正極活物質及びその製造方法並びにその正極活物質を構成要素とする非水電解質電池に関し、より詳しくは、金属リチウム等のアルカリ金属やその合金および化合物等を負極活物質に有する金属リチウム電池、リチウムイオン電池、リチウムポリマー電池等の二次電池に用いられる正極活物質及びその製造方法並びにその方法によって製造される正極活物質を有する二次電池に関する。 The present invention relates to a positive electrode active material for a non-aqueous electrolyte battery, a method for producing the same, and a non-aqueous electrolyte battery including the positive electrode active material as a constituent element. More specifically, the present invention relates to an alkali metal such as metallic lithium or an alloy or compound thereof. The present invention relates to a positive electrode active material used in a secondary battery such as a metal lithium battery, a lithium ion battery, or a lithium polymer battery, a manufacturing method thereof, and a secondary battery having a positive electrode active material manufactured by the method.
金属リチウム等のアルカリ金属やその合金および化合物等を負極活物質に有する金属リチウム電池、リチウムイオン電池、リチウムポリマー電池等の二次電池は、容量が大きく近年脚光を浴びている。このような二次電池の高機能化、高容量化、低コスト化等の観点から、レアメタルフリーの正極活物質として種々の材料が検討されている。例えば特許文献１には、一般式：ＡｙＭＰＯ４（式中、Ａはアルカリ金属、ＭはＣｏとＦｅの両方の組合せからなる遷移金属、０＜ｙ＜２である）で表されるオリビン型遷移金属リン酸錯体を主体とする正極活物質が記載されている。 Secondary batteries such as metallic lithium batteries, lithium ion batteries, and lithium polymer batteries having an alkali metal such as metallic lithium or an alloy or compound thereof as a negative electrode active material have been attracting attention in recent years because of their large capacity. Various materials have been studied as a rare metal-free positive electrode active material from the viewpoints of high functionality, high capacity, low cost, and the like of such secondary batteries. For example, Patent Document 1 discloses an olivine represented by the general formula: A y MPO 4 (wherein A is an alkali metal, M is a transition metal composed of a combination of both Co and Fe, and 0 <y <2). A positive electrode active material mainly composed of a transition metal phosphate complex is described.
遷移金属リン酸錯体のうちでも、アルカリ金属がＬｉであり、遷移金属がＭｎであるリン酸マンガンリチウム（ＬｉＭｎＰＯ４）は、他の遷移金属酸化物系正極活物質に比べて結晶構造中の金属元素間の原子間隔が広いこともあって、オリビン型遷移金属リン酸錯体の中でも特にレート特性が悪いことがわかっている。ＬｉＭｎＰＯ４は、ＬｉＦｅＰＯ４とほぼ同じ約１７０ｍＡｈ／ｇの理論容量を持ちながら、低レート放電条件下にあってもＬｉＦｅＰＯ４に比べ利用率が非常に悪いという問題が多くの文献で指摘されてきた（非特許文献１等）。 Among the transition metal phosphate complexes, lithium manganese phosphate (LiMnPO 4 ) in which the alkali metal is Li and the transition metal is Mn is a metal in a crystal structure as compared with other transition metal oxide positive electrode active materials. It is known that rate characteristics are particularly bad among olivine-type transition metal phosphate complexes due to the wide atomic spacing between elements. LiMnPO 4, while has a theoretical capacity of about the same about 170mAh / g and LiFePO 4, the low rate there to discharge conditions compared to LiFePO 4 utilization is a problem that the very poor have been pointed out in many of the literature (Non-patent document 1 etc.).
表１はオリビン型ＬｉＭＰＯ４正極の特性を比較したものである。一般にこれらリン酸系オリビン正極は、ＰＯ４の共有結合性が強いために、現行コバルト酸リチウム正極よりも熱安定性が優れていることで注目されている。なかでもレアメタルフリーな鉄を使用した鉄オリビンが最も注目されているが、表１からわかるように、ＬｉＦｅＰＯ４正作動電圧が３．４Ｖと低いためにエネルギー密度がそれほど大きくない。そこで、より大きなエネルギー密度を得ようとした場合ＬｉＣｏＰＯ４やＬｉＮｉＰＯ４が好ましいが、これらは返って作動電圧が高すぎるために、現行有機系電解液ではその高電位に耐え切れず電解液が酸化分解されてしまい、長期サイクルを行うことがでない。一方、ＬｉＭｎＰＯ４は、作動電圧が４．０Ｖと現行電解液に対しても使用可能であり、安価かつ安全で、高エネルギー密度な正極として期待できる。しかし、ＬｉＭｎＰＯ４はＬｉＦｅＰＯ４に比べて報告例が多くなく、ＬｉＭｎＰＯ４の電子伝導性が他のリン酸オリビン正極に比べ格段に悪いために、充放電レートをかなり下げない限り、十分な容量が得られないといった問題がある。 Table 1 compares the characteristics of the olivine-type LiMPO 4 positive electrode. In general, these phosphoric acid-based olivine positive electrodes are attracting attention because they are superior in thermal stability to current lithium cobaltate positive electrodes because of the strong covalent bonding of PO 4 . Among them, iron olivine using rare metal-free iron is most noted, but as can be seen from Table 1, the LiFePO 4 positive operating voltage is as low as 3.4 V, so the energy density is not so high. Therefore, LiCoPO 4 and LiNiPO 4 are preferable when trying to obtain a larger energy density. However, since these operating voltages are too high, the current organic electrolyte does not withstand the high potential and the electrolyte is oxidized. It will be broken down and will not be able to do a long cycle. On the other hand, LiMnPO 4 can be used for the current electrolyte with an operating voltage of 4.0 V, and can be expected as a positive electrode that is inexpensive, safe, and has high energy density. However, LiMnPO 4 has not been reported in many cases as compared with LiFePO 4 and the electronic conductivity of LiMnPO 4 is much worse than that of other olivine phosphate positive electrodes. There is a problem that it cannot be obtained.
例えば、ＬｉＦｅＰＯ４に関しては、そのレート特性向上のために、炭素コート（非特許文献２）や貴金属担持（非特許文献３）、低温合成微粉化による反応表面積拡大（非特許文献４）等の試みが提案され、それなりのレート特性向上効果が認められているが、ＬｉＭｎＰＯ４に関してはこれまで、レート特性向上に明らかな効果があったと認められる方法が報告されたことがなかった。表２にＬｉＦｅＰＯ４に対して有効とされているレート特性改善手法をまとめた。レート特性改善手法としては、拡散パス短縮を目的とした活物質の微粒子化、界面抵抗低減を目的とした活物質の表面炭素コーティング、導電性リン化物を生成させるカルボサーマル処理、そしてバルクの電子伝導性改善を目的とした異元素ドープなどが挙げられるが、これらの手法がどの程度ＬｉＭｎＰＯ４に対して効果的であるかは十分に明らかにされていない。 For example, with regard to LiFePO 4 , in order to improve its rate characteristics, attempts such as carbon coating (Non-patent Document 2), noble metal support (Non-patent Document 3), reaction surface area expansion by low-temperature synthetic pulverization (Non-patent Document 4), etc. However, LiMnPO 4 has never been reported to have been reported to have a clear effect on improving the rate characteristics. Table 2 summarizes the rate characteristic improvement methods that are effective for LiFePO 4 . The rate characteristics improvement methods include active material fine particles for shortening diffusion path, active material surface carbon coating for reducing interface resistance, carbothermal treatment to produce conductive phosphide, and bulk electron conduction. Examples include doping with different elements for the purpose of improving the properties, but how effective these methods are for LiMnPO 4 has not been sufficiently clarified.
本発明の課題は、非水電解質電池、特に非水電解質二次電池に適したレート特性を有する正極活物質及びその正極活物質を容易に量産できる製造方法、並びにこの方法により得られる正極活物質を有する高性能な非水電解質電池を提供することにある。 An object of the present invention is to provide a positive electrode active material having rate characteristics suitable for a non-aqueous electrolyte battery, particularly a non-aqueous electrolyte secondary battery, a production method capable of easily mass-producing the positive electrode active material, and a positive electrode active material obtained by this method It is an object to provide a high-performance non-aqueous electrolyte battery having
上記のような優れた特性を有する正極活物質を製造するために、本発明者らは鋭意検討した結果、本発明を完成するに至った。
すなわち、本発明は以下のものを提供する。
In order to produce a positive electrode active material having such excellent characteristics as described above, the present inventors diligently studied, and as a result, completed the present invention.
That is, the present invention provides the following.
［１］ 金属をドープしたリン酸マンガンリチウムＬｉＭｎ１−ｘＭｘＰＯ４ （式中、０＜ｘ≦０．１であり、Ｍはドープ金属元素を表す）と炭素源とを混合し、得られた混合物を不活性ガス雰囲気中にて熱処理する工程を含む正極活物質の製造方法。 [1] Lithium manganese phosphate doped with metal LiMn 1-x M x PO 4 (where 0 <x ≦ 0.1, M represents a doped metal element) and a carbon source are mixed to obtain The manufacturing method of the positive electrode active material including the process of heat-processing the obtained mixture in inert gas atmosphere.
［２］ 金属元素ＭがＣｏ、Ｎｉ、Ｆｅ、Ｍｇ、Ｚｎ及びＣｕからなる群から選ばれる少なくとも１種の金属元素である、［１］の正極活物質の製造方法。
［３］ 金属元素ＭがＭｇである、［２］の正極活物質の製造方法。
[2] The method for producing a positive electrode active material according to [1], wherein the metal element M is at least one metal element selected from the group consisting of Co, Ni, Fe, Mg, Zn, and Cu.
[3] The method for producing a positive electrode active material according to [2], wherein the metal element M is Mg.
［４］ 炭素源が炭素粒子及び炭素前駆体の少なくとも１つを含む、［１］〜［３］の何れかの製造方法。
［５］ 炭素粒子がアセチレンブラックである、［４］の製造方法。
[4] The method according to any one of [1] to [3], wherein the carbon source includes at least one of carbon particles and a carbon precursor.
[5] The production method of [4], wherein the carbon particles are acetylene black.
［６］ ［１］〜［５］の何れかの方法により製造された正極活物質。
［７］ ［６］の正極活物質を含む正極を有する非水電解質電池。
[6] A positive electrode active material produced by any one of the methods [1] to [5].
[7] A nonaqueous electrolyte battery having a positive electrode including the positive electrode active material according to [6].
［正極活物質］
本発明の製造方法を適用する正極活物質は、金属をドープしたリン酸マンガンリチウムＬｉＭｎ１−ｘＭｘＰＯ４ （式中、０＜ｘ≦０．１であり、Ｍはドープ金属元素を表す）の粒子及びその粒子表面上の炭素を含む。
[Positive electrode active material]
The positive electrode active material to which the production method of the present invention is applied is a metal-doped lithium manganese phosphate LiMn 1-x M x PO 4 (where 0 <x ≦ 0.1, and M represents a doped metal element) ) And carbon on the particle surface.
リン酸マンガンリチウムは斜方晶Ｐｎｍａの空間群を持ち、ＦｅＯ６八面体とＰＯ４四面体が頂点共有および辺共有骨格を形成しており、ａ軸およびｃ軸に平行にＬｉの拡散パスを持っているため、リチウムイオンに対してインターカレーションホストとして機能し得る。 Lithium manganese phosphate has an orthorhombic Pnma space group, FeO 6 octahedron and PO 4 tetrahedron form apex and side sharing skeletons, and a Li diffusion path parallel to the a axis and c axis. Therefore, it can function as an intercalation host for lithium ions.
上記一般式：ＬｉＭｎ１−ｘＭｘＰＯ４において、この化合物中のＭｎ以外のドープ金属元素Ｍは、特に限定されないが、Ｃｏ、Ｎｉ、Ｆｅ、Ｍｇ、Ｚｎ及びＣｕから選ばれる少なくとも１種であることが好ましい。Ｍｎ以外の金属元素Ｍの割合を表するｘは０＜ｘ≦０．１であり、好ましくは０．００３≦ｘ≦０．０５であり、より好ましくは０．００５≦ｘ≦０．０５であり、より好ましくは０．００７≦ｘ≦０．０３、特に０．０１≦ｘ≦０．０３である。本発明の正極活物質はドープ金属の割合が非常に少ない金属ドープリン酸マンガンリチウムを使用することが特徴である。 In the above general formula: LiMn 1-x M x PO 4 , the doped metal element M other than Mn in this compound is not particularly limited, but is at least one selected from Co, Ni, Fe, Mg, Zn and Cu. Preferably there is. X representing the ratio of the metal element M other than Mn is 0 <x ≦ 0.1, preferably 0.003 ≦ x ≦ 0.05, more preferably 0.005 ≦ x ≦ 0.05. Yes, more preferably 0.007 ≦ x ≦ 0.03, especially 0.01 ≦ x ≦ 0.03. The positive electrode active material of the present invention is characterized by using metal-doped lithium manganese phosphate with a very small proportion of doped metal.
図１０を参照されたい。図１０はオリビン型リン酸マンガンリチウムの各マグネシムドープ量におけるレート特性を示している。未ドープ試料が放電容量１ｍＡ／ｃｍ２で１３０ｍＡｈ／ｇ、２ｍＡ／ｃｍ２で１１０ｍＡｈ／ｈの容量を維持しているのに対し、Ｍｇ１％ドープした試料は放電容量１ｍＡ／ｃｍ２で１３６ｍＡｈ／ｇ、２ｍＡ／ｃｍ２でも１２５ｍＡｈ／ｇと良好な容量を維持しており、さらに高レートな放電に対しても、未ドープ試料に比べて大きな容量が維持することがわかる。また、Ｍｇを１％より多くドープすると電流密度が低い領域ではレート特性が低下する傾向にあるが、電流密度が高い領域では良好なレート特性が維持されることがわかる。 Please refer to FIG. FIG. 10 shows the rate characteristics of each olivine type lithium manganese phosphate at each magnesium dope amount. Undoped sample discharge capacity 1 mA / cm 2 at 130mAh / g, 2mA / cm whereas maintains the capacity of 110 mAh / h at 2, Mg1% doped sample discharge capacity 1 mA / cm 2 at 136mAh / g It can be seen that even at 2 mA / cm 2 , a good capacity of 125 mAh / g is maintained, and a large capacity is maintained compared to the undoped sample even for a higher rate discharge. It can also be seen that when Mg is doped more than 1%, the rate characteristic tends to decrease in a region where the current density is low, but a good rate characteristic is maintained in a region where the current density is high.
図１１を参照されたい。図１１はオリビン型リン酸マンガンリチウムの各チタンドープ量におけるレート特性を示している。Ｔｉ１％ドープした試料の容量は低レートでは、未ドープ試料よりもわずかに小さいが、高レートになるにつれて、未ドープ試料に比べて大きな容量が維持され、Ｔｉドープ試料の方が優位であることがわかる。 Please refer to FIG. FIG. 11 shows rate characteristics at each titanium doping amount of olivine type lithium manganese phosphate. The capacity of the sample doped with Ti 1% is slightly smaller than that of the undoped sample at the low rate, but as the rate increases, the capacity is maintained larger than that of the undoped sample, and the Ti-doped sample is superior. I understand.
図１２を参照されたい。図１２は、オリビン型リン酸マンガンリチウムのＭｇ１％ドープ試料及びＴｉ１％ドープ試料の各放電レートに対するエネルギー密度変化を示している。ドープ金属の種類によらずに、ドープ量を１０％以下に抑えてオリビン型リン酸マンガンリチウムの正極活物質を調製することにより、高レート条件において高い放電容量、即ち高いエネルギー密度を有する正極活物質が得られることがわかる。特にリン酸マンガンリチウムは、リン酸鉄リチウムのエネルギー密度を越えることがなかったが、Ｍｇ１％ドープによって、はじめて低レート放電時にリン酸鉄リチウムのエネルギー密度を凌駕することが可能となった（図１３）。 Please refer to FIG. FIG. 12 shows the energy density change with respect to each discharge rate of the Mg 1% doped sample and Ti 1% doped sample of olivine type lithium manganese phosphate. Regardless of the type of doped metal, a positive electrode active material having a high discharge capacity, that is, a high energy density under a high rate condition can be obtained by preparing a positive electrode active material of olivine-type lithium manganese phosphate while suppressing the doping amount to 10% or less. It turns out that a substance is obtained. In particular, lithium manganese phosphate did not exceed the energy density of lithium iron phosphate, but Mg 1% doping allowed it to surpass the energy density of lithium iron phosphate for the first time during low-rate discharge (Fig. 13).
このような本発明の予想外の効果は実験的に見出されたものであり、いかなる理論にも拘束されるものではないが、ドープ量が少ないと、結晶構造に悪影響を及ぼすことなく金属ドープによる材料の導電性向上が効率よく実現することが原因であると考えられる。 Such an unexpected effect of the present invention has been found experimentally and is not bound by any theory. However, if the doping amount is small, the metal doping can be performed without adversely affecting the crystal structure. This is thought to be due to the efficient realization of the improved conductivity of the material.
本発明者等の研究によれば、このような特徴を備えることにより、本発明の正極活物質は非水電解質電池に適した良好なレート特性を有する。リン酸マンガンリチウム（ＬｉＭｎＰＯ４）はレート特性が良好でないことが知られている。このため、リン酸マンガンリチウムを主成分としている正極活物質は良好なレート特性を有しないことが当業者間で予想されていた。しかし、このような予想に反して、本発明の正極活物質はリン酸マンガンリチウムを主成分としているにもかかわらず良好なレート特性を有することが見出され、エネルギー密度に関してはリン酸鉄リチウムを凌駕しうることをはじめて実証したものであって、本発明は先行技術に対して新規であるだけでなく、当業者に全くの予想外のものであると言える。 According to research by the present inventors, the positive electrode active material of the present invention has good rate characteristics suitable for a nonaqueous electrolyte battery by having such characteristics. Lithium manganese phosphate (LiMnPO 4 ) is known to have poor rate characteristics. For this reason, it was anticipated among those skilled in the art that the positive electrode active material which has lithium manganese phosphate as a main component does not have a favorable rate characteristic. However, contrary to this expectation, the positive electrode active material of the present invention was found to have good rate characteristics despite being mainly composed of lithium manganese phosphate, and in terms of energy density, lithium iron phosphate. The present invention has been demonstrated for the first time, and the present invention is not only novel to the prior art, but also completely unexpected to those skilled in the art.
金属ドープしたリン酸マンガンリチウムＬｉＭｎ１−ｘＭｘＰＯ４は、正極中に２５重量％以上、特に５０重量％以上含まれることが好ましい。
金属ドープリン酸マンガンリチウムＬｉＭｎ１−ｘＭｘＰＯ４におけるそれ以外の成分としては、これらの放電電位近辺である３〜５Ｖ付近に放電平坦部をもつＬｉＭｎ２Ｏ４やＬｉＣｏＯ２、ＬｉＮｉＯ２などの４Ｖ級正極活物質やＬｉＣｏＰＯ４、ＬｉＦｅＰＯ４、ＬｉＮｉＰＯ４、ＬｉＣｕＰＯ４等のオリビン型遷移金属リン酸錯体、Ｌｉ３Ｆｅ２（ＰＯ４）３、Ｌｉ３Ｖ２（ＰＯ４）３、Ｌｉ３Ｔｉ２（ＰＯ４）３等のナシコン型遷移金属リン酸錯体などが挙げられる。
The metal-doped lithium manganese phosphate LiMn 1-x M x PO 4 is preferably contained in the positive electrode in an amount of 25% by weight or more, particularly 50% by weight or more.
Other components in the metal-doped lithium manganese phosphate LiMn 1-x M x PO 4 include LiMn 2 O 4 , LiCoO 2 , LiNiO 2 and the like having a discharge flat portion in the vicinity of 3 to 5 V near these discharge potentials. 4V class positive electrode active material, olivine-type transition metal phosphate complexes such as LiCoPO 4 , LiFePO 4 , LiNiPO 4 , LiCuPO 4 , Li 3 Fe 2 (PO 4 ) 3 , Li 3 V 2 (PO 4 ) 3 , Li 3 Ti Examples include NASICON type transition metal phosphate complexes such as 2 (PO 4 ) 3 .
金属ドープリン酸マンガンリチウム粒子の粒子径は、できるだけ小さい方がよく、この粒子径は、遊星ボールミル、超音波、ジェットミル、シェーカー等を使用する粉砕方法によって調整することができる。 The particle diameter of the metal-doped lithium manganese phosphate particles should be as small as possible, and the particle diameter can be adjusted by a pulverization method using a planetary ball mill, ultrasonic wave, jet mill, shaker or the like.
金属ドープリン酸マンガンリチウム粒子及びその表面上の炭素を含めた本発明の正極活物質の粒子径は、好ましくは１μｍ〜５０ｎｍであり、より好ましくは２００ｎｍ〜１００ｎｍである。正極活物質の粒子径が大きすぎると炭素の表面被覆と表面部分還元が不十分で十分な容量が得られない。 The particle diameter of the positive electrode active material of the present invention including metal-doped lithium manganese phosphate particles and carbon on the surface thereof is preferably 1 μm to 50 nm, more preferably 200 nm to 100 nm. When the particle diameter of the positive electrode active material is too large, the surface coating of carbon and partial surface reduction are insufficient, and a sufficient capacity cannot be obtained.
本発明の正極活物質に含まれる炭素の量は、電極基準で、好ましくは２５重量％以下、より好ましくは２５〜５重量％の範囲内である。
炭素粒子は本来大きな表面積を有することが知られており、また炭素を金属ドープリン酸マンガンリチウムの粒子表面に存在させることで、焼結防止効果が奏され、粒子の微細化が促進されることを考慮すると、得られる正極活物質粒子全体の表面積は炭素の付着によってより大きなものになると一般に考えられている。しかし、本発明の正極活物質は、このような当業界の予想に反して、粒子の表面積が比較的低い値を示すことが見出されている。本発明の正極活物質は、粒子径と表面積とが共に低い値を有する点を考慮すると、炭素粒子が平滑な層を形成するように金属ドープリン酸マンガンリチウムの粒子表面に存在して正極活物質粒子表面の凹凸を少なくしているものと考えられる。
The amount of carbon contained in the positive electrode active material of the present invention is preferably 25% by weight or less, more preferably 25 to 5% by weight, based on the electrode.
It is known that carbon particles inherently have a large surface area, and that the presence of carbon on the particle surface of metal-doped lithium manganese phosphate provides a sintering-preventing effect and promotes particle miniaturization. In consideration, it is generally considered that the total surface area of the resulting positive electrode active material particles becomes larger due to the adhesion of carbon. However, it has been found that the positive electrode active material of the present invention shows a relatively low value for the surface area of the particles, contrary to the expectation of the industry. The positive electrode active material of the present invention is present on the surface of the metal-doped lithium manganese phosphate particles so that the carbon particles form a smooth layer, considering that both the particle diameter and the surface area have low values. It is thought that the unevenness of the particle surface is reduced.
本発明の正極活物質は、主として金属ドープリン酸マンガンリチウムと炭素の複合体から成るが、その粒子表面に種々の物質、例えば、ＬｉＭｎ２Ｏ４等別の正極活物質が存在してもよい。 Although the positive electrode active material of the present invention is mainly composed of a composite of metal-doped lithium manganese phosphate and carbon, various positive electrode active materials such as LiMn 2 O 4 may be present on the particle surface.
［正極活物質の製造方法］
本発明の正極活物質は、金属ドープリン酸マンガンリチウムと炭素源とを混合、特に炭素源が化合物表面に分散するように混合し、得られた混合物を不活性ガス雰囲気中にて熱処理する工程を含む方法により製造することができる。
[Method for producing positive electrode active material]
The positive electrode active material of the present invention comprises a step of mixing metal-doped lithium manganese phosphate and a carbon source, particularly mixing the carbon source so that the carbon source is dispersed on the compound surface, and heat-treating the resulting mixture in an inert gas atmosphere. It can manufacture by the method of including.
（金属ドープリン酸マンガンリチウム）
金属ドープリン酸マンガンリチウムは、ＬｉＭｎＰＯ４の原料とドープする金属又はその金属化合物とを混合し、熱処理、溶融急冷、溶融徐冷処理、メカニカルミリング処理、ソノケミカル処理、ゾルゲル法処理等を行うことにより調製できる。例えば、原料の粒状物を混合して熱処理してもよいし、原料の水溶液を混合して得られる生成物にろ過、水洗、乾燥などの処理を施し、熱処理して得られるものでもよい。
(Metal-doped lithium manganese phosphate)
Metal-doped lithium manganese phosphate is prepared by mixing a raw material of LiMnPO 4 and a metal to be doped or a metal compound thereof, and performing heat treatment, melt quenching, melt annealing treatment, mechanical milling treatment, sonochemical treatment, sol-gel treatment, etc. Can be prepared. For example, the raw material granular material may be mixed and heat-treated, or the product obtained by mixing the raw material aqueous solution may be subjected to a treatment such as filtration, washing with water, and drying, followed by heat treatment.
本発明の金属ドープリン酸マンガンリチウムは、ドープ量を上述した範囲に限定する以外は公知の金属ドープリン酸マンガンリチウムの製造方法により製造することができる。より具体的には、出発材料を目的化合物の組成となるように過剰な純水と混合してスラリーを得、このスラリーを酸化性雰囲気下で熱処理することにより製造することができる。均質且つ微細なリン酸マンガンリチウム粒子を得るために、混合を遊星ボールミル、超音波、ジェットミル、シェーカー等の粉砕装置を用いて行うことが好ましい。 The metal-doped lithium manganese phosphate of the present invention can be produced by a known method for producing metal-doped lithium manganese phosphate except that the doping amount is limited to the above-described range. More specifically, it can be produced by mixing a starting material with excess pure water so as to have the composition of the target compound to obtain a slurry, and heat-treating the slurry in an oxidizing atmosphere. In order to obtain homogeneous and fine lithium manganese phosphate particles, mixing is preferably performed using a pulverizer such as a planetary ball mill, an ultrasonic wave, a jet mill, or a shaker.
原料のＭｎ塩及びＭ塩に関して、対陰イオンは、特に限定されず、例えば、硫酸塩、硝酸塩、塩酸塩、酢酸塩等を使用することができる。得られる正極活物質中に不純物を残留させないという観点から、酢酸塩等の有機酸塩、硫酸塩等を用いることが好ましい。 With respect to the raw material Mn salt and M salt, the counter anion is not particularly limited, and for example, sulfate, nitrate, hydrochloride, acetate and the like can be used. From the viewpoint of preventing impurities from remaining in the obtained positive electrode active material, it is preferable to use an organic acid salt such as acetate, a sulfate, or the like.
リチウム源としては、炭酸リチウム、酢酸リチウム、水酸化リチウム、塩化リチウム、蓚酸リチウム等が挙げられる。
マンガン源としては、マンガン粉、酸化マンガン、炭酸マンガン、酢酸マンガン、水酸化マンガン、塩化マンガン、蓚酸マンガン等が挙げられる。
Examples of the lithium source include lithium carbonate, lithium acetate, lithium hydroxide, lithium chloride, and lithium oxalate.
Examples of the manganese source include manganese powder, manganese oxide, manganese carbonate, manganese acetate, manganese hydroxide, manganese chloride, and manganese oxalate.
リン酸源としては、五酸化リン、リン酸、リン酸二水素アンモニウム、リン酸水素二アンモニウム等を挙げることができる。熱処理過程で副生成物であるアンモニアガスの発生が少ないことが好ましいため、五酸化リンやリン酸が好適である。但し、原料としてリン酸を用いる場合には、通常リン酸は水溶液の状態で市販されているために、その含有率（純度）を滴定等によって正確に求めた後に使用することが好ましい。 Examples of the phosphoric acid source include phosphorus pentoxide, phosphoric acid, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, and the like. Phosphorus pentoxide and phosphoric acid are preferred because it is preferable that ammonia gas as a by-product be generated little during the heat treatment process. However, when phosphoric acid is used as a raw material, since phosphoric acid is usually marketed in the form of an aqueous solution, it is preferably used after its content (purity) is accurately determined by titration or the like.
また、原料の水溶液の混合によって得られる生成物を熱処理前の原料に用いた場合には、均質で結晶性が良いリン酸マンガンリチウムを主成分とする化合物を製造することができる。 Moreover, when the product obtained by mixing the aqueous solution of the raw material is used as the raw material before the heat treatment, it is possible to produce a compound mainly composed of lithium manganese phosphate that is homogeneous and has good crystallinity.
金属ドープリン酸マンガンリチウムの熱処理は、例えば、常温〜熱処理完了温度（１００℃〜８００℃、より好ましくは３００℃から６５０℃）までの１段階の昇温および保持過程にて行うことができる。また、低温域（常温〜３００℃）での熱処理過程（仮焼成）と高温域（３００℃〜８００℃）での熱処理過程（本焼成）の２段階に分けて行うこともできる。例えば、リン酸水溶液にリチウム源として炭酸リチウム、マンガン源として金属マンガン粉を化学量論比で混入し、マグネットスターラーを用いて２日間攪拌反応後、大気中にて１００℃〜６００℃で２４時間熱処理することにより、熱処理温度によって、結晶体や非晶質体のリン酸マンガンリチウムを合成することもできる。さらに、１１００℃以上に昇温し、一気に溶融徐冷、もしくは溶融急冷させることによっても、冷却速度によって、結晶体や非晶質体のリン酸マンガンリチウムを合成することができる。 The heat treatment of the metal-doped lithium manganese phosphate can be performed, for example, in a one-step temperature increase and holding process from room temperature to a heat treatment completion temperature (100 ° C. to 800 ° C., more preferably 300 ° C. to 650 ° C.). Further, the heat treatment process (temporary firing) in a low temperature range (normal temperature to 300 ° C.) and the heat treatment process (main firing) in a high temperature range (300 ° C. to 800 ° C.) can be performed. For example, lithium carbonate as a lithium source and metal manganese powder as a manganese source are mixed in a stoichiometric ratio in a phosphoric acid aqueous solution, stirred for 2 days using a magnetic stirrer, and then in air at 100 ° C. to 600 ° C. for 24 hours. By heat treatment, crystalline or amorphous lithium manganese phosphate can be synthesized depending on the heat treatment temperature. Furthermore, crystalline or amorphous lithium manganese phosphate can also be synthesized at a cooling rate by raising the temperature to 1100 ° C. or higher and melting or cooling at once or melting and quenching.
（炭素源）
炭素源は、炭素粒子及び熱処理により炭素に変化する炭素前駆体の少なくとも一方を含む。炭素源として炭素前駆体を使用すると、比較的低温で、低い表面積を有する正極活物質を製造することができる。
(Carbon source)
The carbon source includes at least one of carbon particles and a carbon precursor that changes to carbon by heat treatment. When a carbon precursor is used as the carbon source, a positive electrode active material having a low surface area can be produced at a relatively low temperature.
炭素粒子としては、公知のものを制限無く使用でき、例えば、アセチレンブラック、ケッチェンブラック等のカーボンブラック；ピッチコークス、メソカーボンマイクロビーズ、カーボンナノチューブ、炭素繊維等が挙げられる。炭素前駆体としては、例えば、ポリビニリデンフルオライド（ＰＶｄＦ）、ポリビニルアルコール、ポリオレフィン類、ポリアクリロニトリル、セルロース、デンプン、グラニュー糖等の合成及び天然の有機高分子化合物（特に、水溶性のもの）；アセトン、アクリロニトリル、ジビニルベンゼン、ビニルアセテート等の重合性単量体（特に、炭素−炭素二重結合を有する不飽和有機化合物）等が挙げられる。 As the carbon particles, known ones can be used without limitation, and examples thereof include carbon blacks such as acetylene black and ketjen black; pitch cokes, mesocarbon micro beads, carbon nanotubes, and carbon fibers. Examples of carbon precursors include synthetic and natural organic polymer compounds (particularly water-soluble compounds) such as polyvinylidene fluoride (PVdF), polyvinyl alcohol, polyolefins, polyacrylonitrile, cellulose, starch, and granulated sugar; Examples thereof include polymerizable monomers (particularly unsaturated organic compounds having a carbon-carbon double bond) such as acetone, acrylonitrile, divinylbenzene, and vinyl acetate.
炭素源の添加量は限定されないが、熱処理後に残留する炭素分が正極として過剰にならない範囲であることは言うまでもなく、好ましくは、電極基準で、２５重量％以下、特に２５〜５重量％の範囲で添加することが望ましい。添加は前述した粉砕装置を使用して行うことが均質な混合物を得る上で好ましい。 The amount of carbon source added is not limited, but it goes without saying that the carbon content remaining after the heat treatment does not become excessive as the positive electrode, preferably 25 wt% or less, particularly 25 to 5 wt%, based on the electrode. It is desirable to add at. The addition is preferably performed using the above-described pulverizer in order to obtain a homogeneous mixture.
（熱処理工程）
熱処理工程は、金属ドープリン酸マンガンリチウム及び炭素源の混合物に熱エネルギーを供給することにより、その化合物粒子表面に炭素を安定に存在させ、不純物を気化させ除去し、本発明の正極活物質の粒子を生成する工程である。上述のようにして得られた金属ドープリン酸マンガンリチウムのみでは、導電性は十分ではなく、良好なレート特性を発現しえない。そこで、金属ドープリン酸マンガンリチウムのレート特性を改善するために、炭素源と共に不活性ガス雰囲気下で熱処理する本工程が本発明の正極活物質を製造するために必要である。
(Heat treatment process)
In the heat treatment step, by supplying thermal energy to the mixture of the metal-doped lithium manganese phosphate and the carbon source, carbon is stably present on the surface of the compound particles, impurities are vaporized and removed, and the particles of the positive electrode active material of the present invention Is a step of generating. Only the metal-doped lithium manganese phosphate obtained as described above is insufficient in conductivity and cannot exhibit good rate characteristics. Therefore, in order to improve the rate characteristics of the metal-doped lithium manganese phosphate, this step of heat treatment in an inert gas atmosphere together with the carbon source is necessary for producing the positive electrode active material of the present invention.
熱処理は、不活性ガス雰囲気下で行われる。不活性ガスとしては、窒素、ヘリウム、ネオン、アルゴン等が挙げられる。
本発明の正極活物質の特徴はまた、このような金属ドープリン酸マンガンリチウムの粒子表面上に不活性ガス雰囲気下で熱処理（カルボサーマル処理）を行い炭素を存在させた点にある。
The heat treatment is performed in an inert gas atmosphere. Examples of the inert gas include nitrogen, helium, neon, and argon.
The positive electrode active material of the present invention is also characterized in that carbon is present by heat treatment (carbothermal treatment) in an inert gas atmosphere on the surface of such metal-doped lithium manganese phosphate particles.
図１８を参照されたい。オリビン型リン酸マンガンリチウムとアセチレンブラックを７０：２５の重量比で測り取り、遊星ミルで２００ｒｐｍ、２４時間乾式混合にてカーボンコート処理を行い、その後、アルゴン雰囲気中１００−９００℃で１時間アニール処理を行うことでこのカルボサーマル処理の処理温度に対する放電容量変化を示す。図１８中、４００℃〜５００℃の温度範囲で放電容量が急激に上昇し、最も大きな容量は５００℃付近でカルボサーマル処理を行った試料から得られ、それ以上の高温でカルボサーマル処理を行うと容量は返って低下してしまうことがわかる。添加炭素が正極試料表面の酸素と反応し二酸化炭素として気化する温度が４００℃付近であり、この酸化反応に伴いＭｎ３＋がＭｎ２＋に還元されて材料の導電性が向上することが、４００℃付近での放電容量の急激な上昇の原因であると考えられる。図１８中のＳＥＭ写真は５００℃および９００℃でカルボサーマル処理を行った試料のＳＥＭ写真を示しているが、９００℃でカルボサーマル処理した試料は粒子成長が起こっていることがわかる。５００℃付近から温度の上昇に伴って粒子成長が起こり、粒子の表面積が低下することにより放電容量の低下が起こると考えられる。 See FIG. Olivine-type lithium manganese phosphate and acetylene black were measured at a weight ratio of 70:25, carbon-coated by dry mixing at a planetary mill at 200 rpm for 24 hours, and then annealed at 100-900 ° C. for 1 hour in an argon atmosphere. By performing the treatment, the change in discharge capacity with respect to the treatment temperature of the carbothermal treatment is shown. In FIG. 18, the discharge capacity rapidly increases in the temperature range of 400 ° C. to 500 ° C., and the largest capacity is obtained from the sample subjected to carbothermal treatment at around 500 ° C., and carbothermal treatment is performed at a higher temperature. It can be seen that the capacity decreases. The temperature at which the added carbon reacts with oxygen on the surface of the positive electrode sample and vaporizes as carbon dioxide is around 400 ° C., and this oxidation reaction reduces Mn 3+ to Mn 2+ to improve the conductivity of the material. This is considered to be a cause of a rapid increase in discharge capacity in the vicinity. The SEM photographs in FIG. 18 show SEM photographs of samples subjected to carbothermal treatment at 500 ° C. and 900 ° C., and it can be seen that particle growth occurs in the sample subjected to carbothermal treatment at 900 ° C. It is considered that particle growth occurs as the temperature increases from around 500 ° C., and the discharge capacity decreases due to a decrease in the surface area of the particles.
本発明の金属ドープオリビン型リン酸マンガンリチウムは金属ドープ量が１０％以下と非常に少ないので、未ドープオリビン型リン酸マンガンリチウムと同様に、その放電容量が熱処理温度に依存すると考えられる。実際に本発明の金属ドープオリビン型リン酸マンガンリチウムにおいても炭素添加熱処理（カルボサーマル処理）を行うことにより充放電特性が飛躍的に向上することが確認できた（図１９）。従って、本発明において、熱処理工程は、添加炭素が正極試料表面の酸素を奪って気化する温度で通常行い、好ましくは２５０℃以上、より好ましくは４００〜６００℃、特に５００℃程度の温度で行う。また熱処理温度が高すぎるとかえって放電容量が低下するので、８００℃を超えない温度で、特に７００℃を超えない温度で行うことが好ましい。 Since the metal-doped olivine type lithium manganese phosphate of the present invention has a metal doping amount as very low as 10% or less, the discharge capacity is considered to depend on the heat treatment temperature in the same manner as the undoped olivine type lithium manganese phosphate. In fact, it was confirmed that the charge / discharge characteristics of the metal-doped olivine-type lithium manganese phosphate of the present invention were drastically improved by performing carbon addition heat treatment (carbothermal treatment) (FIG. 19). Therefore, in the present invention, the heat treatment step is usually performed at a temperature at which the added carbon vaporizes oxygen on the surface of the positive electrode sample, preferably 250 ° C. or higher, more preferably 400 to 600 ° C., particularly about 500 ° C. . Further, since the discharge capacity is lowered when the heat treatment temperature is too high, it is preferable to carry out the treatment at a temperature not exceeding 800 ° C., particularly not exceeding 700 ° C.
熱処理時間は、通常、数時間未満、好ましくは３０分〜２時間、特に１時間程度である。
炭素源を金属ドープリン酸マンガンリチウムに添加して熱処理を行う本工程においては、炭素源が熱処理中に金属ドープリン酸マンガンリチウムの分解により生成するガスにより発泡することを防ぐことができ、その結果、融解状態にある炭素源がより均一に金属ドープリン酸マンガンリチウムの表面に溶融状態で広がり、より均一に炭素を金属ドープリン酸マンガンリチウム粒子表面に析出させることができる。このため、得られる正極活物質の表面導電性がさらに良好になり、また粒子間の接触が強固に安定化される。
The heat treatment time is usually less than several hours, preferably 30 minutes to 2 hours, particularly about 1 hour.
In this step of performing a heat treatment by adding a carbon source to metal-doped lithium manganese phosphate, the carbon source can be prevented from foaming due to the gas generated by the decomposition of the metal-doped lithium manganese phosphate during the heat treatment. The carbon source in the molten state spreads more uniformly on the surface of the metal-doped lithium manganese phosphate, and the carbon can be more uniformly deposited on the surface of the metal-doped lithium manganese phosphate particles. For this reason, the surface conductivity of the positive electrode active material obtained is further improved, and the contact between the particles is firmly stabilized.
以上のようにして得られる本発明の正極活物質は、リチウム負極に対して平坦で可逆な４Ｖ放電平坦部を示し、非水電解質電池、特に非水電解質二次電池の構成材料として好適に用いることができる。本発明の正極活物質は、各種カチオンの挿入・脱離により二次電池の電極活物質として機能し得る。挿入・脱離するカチオンとしては、特にリチウムイオンが好ましい。 The positive electrode active material of the present invention obtained as described above exhibits a flat and reversible 4V discharge flat portion with respect to the lithium negative electrode, and is suitably used as a constituent material of a nonaqueous electrolyte battery, particularly a nonaqueous electrolyte secondary battery. be able to. The positive electrode active material of the present invention can function as an electrode active material of a secondary battery by inserting and removing various cations. As the cation to be inserted / extracted, lithium ion is particularly preferable.
［非水電解質電池］
本発明の正極活物質を有する電極は、コイン型、円筒型、角型等の各種形状の電池の電極として好適に用いることができる。例えば、この電極活物質を圧縮成形してペレット状等の電極を形成することができる。また、金属等の導電性材料からなる集電体に上記電極活物質を付着させることによって、板状またはシート状の電極を形成することができる。
[Nonaqueous electrolyte battery]
The electrode having the positive electrode active material of the present invention can be suitably used as an electrode for batteries having various shapes such as a coin shape, a cylindrical shape, and a square shape. For example, the electrode active material can be compression-molded to form a pellet-shaped electrode. A plate-like or sheet-like electrode can be formed by attaching the electrode active material to a current collector made of a conductive material such as metal.
（電池の構造）
本発明の正極活物質を用いた非水電解質電池の一例を添付図面を用いて説明する。図２０は電池の概略を示す断面図である。この図において非水電解質電池１は、大まかに言って電池の外部負極として機能する負極部材２と、電池の外部正極として機能する正極部材３と、両部材間に負極集電体４、負極活物質５、セパレータ８、正極活物質７及び正極集電体６をこの順番で有してなる。負極部材２はほぼ円筒形をしており、その内部に負極集電体４及び負極活物質５を収容できるように構成されている。一方、正極部材３もほぼ円筒形をしており、その内部に正極集電体６及び正極活物質７を収容できるように構成されている。正極部材３及びセパレータ８の半径方向の寸法は負極部材２のものよりもやや大きめに設定されており、負極部材２の周端部とセパレータ８及び正極部材３の周端部とが重なり合うようになっている。電池内部の空間は非水電解質９が充填され、負極部材２、セパレータ８及び正極部材３の周端部の重なり合う部分には封止材１０が施されて、電池内部が気密状態に保たれている。
(Battery structure)
An example of a nonaqueous electrolyte battery using the positive electrode active material of the present invention will be described with reference to the accompanying drawings. FIG. 20 is a cross-sectional view schematically showing the battery. In this figure, a non-aqueous electrolyte battery 1 generally includes a negative electrode member 2 that functions as an external negative electrode of the battery, a positive electrode member 3 that functions as an external positive electrode of the battery, a negative electrode current collector 4, a negative electrode active material between the two members. It has the substance 5, the separator 8, the positive electrode active material 7, and the positive electrode collector 6 in this order. The negative electrode member 2 has a substantially cylindrical shape, and is configured to accommodate the negative electrode current collector 4 and the negative electrode active material 5 therein. On the other hand, the positive electrode member 3 also has a substantially cylindrical shape, and is configured to accommodate the positive electrode current collector 6 and the positive electrode active material 7 therein. The dimensions of the positive electrode member 3 and the separator 8 in the radial direction are set slightly larger than those of the negative electrode member 2 so that the peripheral end portions of the negative electrode member 2 and the peripheral end portions of the separator 8 and the positive electrode member 3 overlap each other. It has become. The space inside the battery is filled with a non-aqueous electrolyte 9, and a sealing material 10 is applied to the overlapping portions of the peripheral ends of the negative electrode member 2, the separator 8, and the positive electrode member 3 to keep the inside of the battery airtight. Yes.
負極は、負極部材２を外部負極として、それに接する負極集電体４、及び負極集電体上の負極活物質５の層が形成されてなる。負極集電体としては、例えばニッケル箔、銅箔等が用いられる。負極活物質としては、リチウムをドープ／脱ドープ可能なものを用い、具体的には、金属リチウム、リチウム合金、リチウムがドープされた導電性高分子、層状化合物（炭素材料や金属酸化物等）等を用いる。負極活物質層に含有される結着材としては、ポリフッ化ビニリデン（ＰＶｄＦ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリフッ化ビニリデン−ヘキサフルオロプロピレン共重合体（ＰＶｄＦ−ＨＦＰ）等を用いることができる。特に、金属リチウム箔は負極活物質としてのみならず負極集電体としても用いることができるので、負極に金属リチウム箔を使用することにより電池構造を簡易なものとすることができる。 The negative electrode has a negative electrode current collector 4 as an external negative electrode, and a negative electrode current collector 4 in contact with the negative electrode member 2 and a negative electrode active material 5 layer on the negative electrode current collector. As the negative electrode current collector, for example, nickel foil, copper foil or the like is used. As the negative electrode active material, a material capable of doping / de-doping lithium is used. Specifically, lithium metal, lithium alloy, conductive polymer doped with lithium, layered compound (carbon material, metal oxide, etc.) Etc. are used. As the binder contained in the negative electrode active material layer, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyvinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP), or the like can be used. . In particular, since the metal lithium foil can be used not only as the negative electrode active material but also as the negative electrode current collector, the battery structure can be simplified by using the metal lithium foil for the negative electrode.
正極は、正極部材３を外部正極として、それに接する正極集電体６、及び正極集電体上の正極活物質７の層が形成されてなる。正極活物質として、上述した本発明の正極活物質を使用する。正極集電体としては、例えばアルミニウム箔等が用いられる。正極活物質層に含有される結着材としては、ポリフッ化ビニリデン（ＰＶｄＦ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリフッ化ビニリデン−ヘキサフルオロプロピレン共重合体（ＰＶｄＦ−ＨＦＰ）等を用いることができる。正極活物質層には、導電性を向上させるために導電材を配合することができる。この導電材としては、例えば、グラファイト、アセチレンブラック等が挙げられる。 The positive electrode comprises a positive electrode current collector 6 as an external positive electrode, and a positive electrode current collector 6 in contact with the positive electrode member 3 and a positive electrode active material 7 layer on the positive electrode current collector. The positive electrode active material of the present invention described above is used as the positive electrode active material. For example, an aluminum foil or the like is used as the positive electrode current collector. As the binder contained in the positive electrode active material layer, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), polyvinylidene fluoride-hexafluoropropylene copolymer (PVdF-HFP), or the like can be used. . A conductive material can be blended in the positive electrode active material layer in order to improve conductivity. Examples of the conductive material include graphite and acetylene black.
セパレータ８は、正極と負極とを離間させるものであり、この種の非水電解質電池のセパレータとして通常用いられている公知の材料を用いることができ、例えば、ポリプロピレン等の高分子フィルム、ポリエチレンカーボネート多孔質膜等が用いられる。また、リチウムイオン伝導度とエネルギー密度との関係から、セパレータの厚みはできるだけ薄いことが望ましい。具体的には、セパレータの厚みは例えば５０μｍ以下が好ましい。 The separator 8 separates the positive electrode and the negative electrode, and a known material that is usually used as a separator for this type of non-aqueous electrolyte battery can be used. For example, a polymer film such as polypropylene, polyethylene carbonate, etc. A porous membrane or the like is used. In addition, it is desirable that the thickness of the separator is as thin as possible from the relationship between lithium ion conductivity and energy density. Specifically, the thickness of the separator is preferably 50 μm or less, for example.
封止材１０としては、この種の非水電解質電池の正極活物質層の封止材として通常用いられている公知の樹脂材料等を用いることができる。
非水電解質としては、液体電解質のみならず、固体電解質、溶媒を含有するゲル状電解質など種々の形態のものが使用できる。液体電解質としては、非プロトン性非水溶媒に電解質を溶解させた溶液を用いる。
As the sealing material 10, a known resin material or the like that is usually used as a sealing material for the positive electrode active material layer of this type of nonaqueous electrolyte battery can be used.
As the non-aqueous electrolyte, not only a liquid electrolyte but also various forms such as a solid electrolyte and a gel electrolyte containing a solvent can be used. As the liquid electrolyte, a solution in which an electrolyte is dissolved in an aprotic nonaqueous solvent is used.
非水溶媒としては、例えば、エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、ビニレンカーボネート等の環状カーボネート類、ジメチルカーボネート、ジエチルカーボネート、ジプロピルカーボネート、エチルメチルカーボネート等の鎖状カーボネート類、γ−ブチロラクトン等のラクトン類、１，２−ジメトキシエタン、１，２−ジエトキシエタン、ジオキサン、１，３−ジオキソラン、３−メチル１，３−ジオキソラン、ニトロメタン、Ｎ，Ｎ−ジメチルホルムアミド、ジメチルスルホキシド、スルホラン等のスルホン類、プロピオン酸メチル、酪酸メチル等のエステル類、アセトニトリル、プロピオニトリル等のニトリル類、テトラヒドロフラン、２−メチルテトラヒドロフラン等のエーテル類等を挙げることができる。特に、電圧安定性の点からは、エチレンカーボネート、プロピレンカーボネート、ビニレンカーボネート等の環状カーボネート類、ジメチルカーボネート、ジエチルカーボネート、ジプロピルカーボネート等の鎖状カーボネート類を使用することが好ましい。また、このような非水溶媒は、１種類を単独で用いてもよいし、２種類以上を混合して用いてもよい。 Examples of the non-aqueous solvent include cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, and vinylene carbonate, chain carbonates such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and ethyl methyl carbonate, and γ-butyrolactone. Lactones, 1,2-dimethoxyethane, 1,2-diethoxyethane, dioxane, 1,3-dioxolane, 3-methyl 1,3-dioxolane, nitromethane, N, N-dimethylformamide, dimethyl sulfoxide, sulfolane, etc. Examples include sulfones, esters such as methyl propionate and methyl butyrate, nitriles such as acetonitrile and propionitrile, and ethers such as tetrahydrofuran and 2-methyltetrahydrofuran. Can. In particular, from the viewpoint of voltage stability, it is preferable to use cyclic carbonates such as ethylene carbonate, propylene carbonate, and vinylene carbonate, and chain carbonates such as dimethyl carbonate, diethyl carbonate, and dipropyl carbonate. Moreover, such a non-aqueous solvent may be used individually by 1 type, and may be used in mixture of 2 or more types.
電解質としては、例えば、ＬｉＰＦ６、ＬｉＣｌＯ４、ＬｉＡｓＦ６、ＬｉＢＦ４、ＬｉＣＦ３ＳＯ３、ＬｉＮ（ＣＦ３ＳＯ２）２、ＬｉＣ４Ｆ９ＳＯ３、ＬｉＣ（ＣＦ３ＳＯ２）３、ＬｉＣｌＯ４等のリチウム化合物（リチウム塩）等のリチウム塩を使用することができる。これらのリチウム塩の中でも、ＬｉＰＦ６、ＬｉＢＦ４を使用することが好ましい。電解質は一種または二種以上を用いることができる。 Examples of the electrolyte include LiPF 6 , LiClO 4 , LiAsF 6 , LiBF 4 , LiCF 3 SO 3 , LiN (CF 3 SO 2 ) 2 , LiC 4 F 9 SO 3 , LiC (CF 3 SO 2 ) 3 , LiClO 4. Lithium salts such as lithium compounds (lithium salts) can be used. Among these lithium salts, it is preferable to use LiPF 6 or LiBF 4 . One or two or more electrolytes can be used.
また、固体電解質としては、窒化リチウム、ヨウ化リチウム等の無機固体電解質；ポリ（エチレンオキサイド）、ポリ（メタクリレート）、ポリ（アクリレート）等の有機高分子電解質等が挙げられる。更に、ゲル状電解質を形成するための材料としては、上記液体電解質を吸収してゲル化できる材料であれば特に制限無く使用することができ、例えば、ポリ（ビニリデンフルオライド）、ビニリデンフルオライド／ヘキサフルオロプロピレン共重合体などの含フッ素重合体が挙げられる。 Examples of the solid electrolyte include inorganic solid electrolytes such as lithium nitride and lithium iodide; organic polymer electrolytes such as poly (ethylene oxide), poly (methacrylate), and poly (acrylate). Furthermore, the material for forming the gel electrolyte can be used without particular limitation as long as it is a material capable of gelling by absorbing the liquid electrolyte. For example, poly (vinylidene fluoride), vinylidene fluoride / Examples thereof include fluorine-containing polymers such as hexafluoropropylene copolymers.
（電池の製造方法）
本発明の正極活物質を使用した非水電解質電池は、例えば、以下のように製造される。
まず、負極の製造方法から説明する。負極活物質と結着材とを溶媒中に分散させてスラリーを調製する。得られたスラリーを集電体上に均一に塗布、乾燥して負極活物質層を形成する。得られた負極集電体及び負極活物質層からなる積層体を負極部材内に負極集電体と負極部材内面が接するように収容して負極が形成される。また、前述したように負極活物質及び負極活物質として金属リチウム箔をそのまま用いることもできる。
(Battery manufacturing method)
The nonaqueous electrolyte battery using the positive electrode active material of the present invention is manufactured as follows, for example.
First, the negative electrode manufacturing method will be described. A negative electrode active material and a binder are dispersed in a solvent to prepare a slurry. The obtained slurry is uniformly applied on a current collector and dried to form a negative electrode active material layer. The obtained laminate including the negative electrode current collector and the negative electrode active material layer is accommodated in the negative electrode member so that the negative electrode current collector and the inner surface of the negative electrode member are in contact with each other to form a negative electrode. Further, as described above, the metal lithium foil can be used as it is as the negative electrode active material and the negative electrode active material.
次に正極の製造方法を説明する。本発明の正極活物質、導電材及び結着材を溶媒中に分散させてスラリーを調製する。スラリーを集電体上に均一に塗布、乾燥して正極活物質層を形成する。得られた正極集電体及び正極活物質層からなる積層体を正極部材内に正極集電体と正極部材内面が接するように収容して正極が形成される。 Next, the manufacturing method of a positive electrode is demonstrated. A positive electrode active material, a conductive material, and a binder of the present invention are dispersed in a solvent to prepare a slurry. The slurry is uniformly applied on the current collector and dried to form a positive electrode active material layer. The obtained laminate of the positive electrode current collector and the positive electrode active material layer is accommodated in the positive electrode member so that the positive electrode current collector and the inner surface of the positive electrode member are in contact with each other, thereby forming a positive electrode.
非水電解質は、液状のものを採用する場合は、電解質塩を非水溶媒中に溶解することにより調製される。
上述のようにして製造された負極及び正極を、負極活物質層と正極活物質層との間にセパレータが介在するように重ね合わせ、非水電解質を充填し、封止材により電池内部を密封することにより、非水電解質電池が完成する。
When a nonaqueous electrolyte is used, it is prepared by dissolving an electrolyte salt in a nonaqueous solvent.
The negative electrode and the positive electrode manufactured as described above are overlapped so that a separator is interposed between the negative electrode active material layer and the positive electrode active material layer, filled with a nonaqueous electrolyte, and the inside of the battery is sealed with a sealing material. By doing so, a non-aqueous electrolyte battery is completed.
本発明の非水電解質電池は、その形状については特に限定されることはなく、円筒型、角型、コイン型、ボタン型等の形状とすることができ、また、薄型、大型等の種々の大きさにすることができる。また、本発明は、一次電池についても二次電池についても適用可能である。 The shape of the nonaqueous electrolyte battery of the present invention is not particularly limited, and can be a cylindrical shape, a square shape, a coin shape, a button shape, or the like, and various types such as a thin shape and a large size are available. Can be sized. The present invention can be applied to both a primary battery and a secondary battery.
［実施例］
以下、本発明を実施例に基づき詳細に説明するが、本発明はこれらの実施例に限定されるものではない。
[Example]
EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these Examples.
１．実験方法
（Ｍｇドープ試料の合成）
出発原料にリチウム源として炭酸リチウム（Ｌｉ２ＣＯ３、Ｗａｋｏ ９８％）、マンガン源としてマンガン粉（Ｍｎ、Ｗａｋｏ ９８％）、Ｍｇ源としてマグネシウムエトキシド（Ｍｇ（Ｃ２Ｈ５Ｏ）２、Ｗａｋｏ ９８％）、リン源として五酸化二リン（Ｐ２Ｏ５、Ｗａｋｏ ９８％）をグローブボックス内で化学量論比に秤量した（合計で１０ｇ）。その後、ドラフト内にて過剰な純水（５０ｍｌ）加え、マグネットスターラーを用いて２日間攪拌し、反応させた。その後完全に反応させるために、遊星ミル（伊藤製作所製遊星ミルＬＰ４／２）にて２００ｒｐｍ、２４時間攪拌し、大気中にてそれぞれ３５０℃で２４時間熱処理を行った。遊星ミルで攪拌する際、直径１０ｍｍのボール５個と直径３ｍｍのボールを合計で１００ｇになるように加えた。
1. Experimental method (synthesis of Mg-doped sample)
Lithium carbonate (Li 2 CO 3 , Wako 98%) as a lithium source, manganese powder (Mn, Wako 98%) as a manganese source, magnesium ethoxide (Mg (C 2 H 5 O) 2 , Wako as a Mg source 98%) and diphosphorus pentoxide (P 2 O 5 , Wako 98%) as a phosphorus source were weighed to a stoichiometric ratio in the glove box (10 g in total). Thereafter, excess pure water (50 ml) was added in the draft, and the mixture was stirred for 2 days using a magnetic stirrer to cause a reaction. Thereafter, in order to complete the reaction, the mixture was stirred for 24 hours at 200 rpm in a planetary mill (Planet Mill LP4 / 2 manufactured by Ito Seisakusho), and heat-treated at 350 ° C. for 24 hours in the atmosphere. When stirring with a planetary mill, 5 balls with a diameter of 10 mm and 3 mm with a diameter were added to a total of 100 g.
（Ｔｉドープ試料の合成）
出発原料にリチウム源として炭酸リチウム（Ｌｉ２ＣＯ３、Ｗａｋｏ ９８％）、マンガン源としてマンガン粉（Ｍｎ、Ｗａｋｏ ９８％）、Ｔｉ源としてチタンイソプロポキシド（Ｔｉ［（ＣＨ３）２ＣＨＯ］４、Ｗａｋｏ ９５％）、リン源として五酸化二リン（Ｐ２Ｏ５、Ｗａｋｏ ９８％）をグローブボックス内で化学量論比に秤量した（合計で１０ｇ）。その後、ドラフト内にて過剰な純水（５０ｍｌ）加え、マグネットスターラーを用いて２日間攪拌し、反応させた。その後完全に反応させるために、遊星ミル（伊藤製作所製遊星ミルＬＰ４／２）にて２００ｒｐｍ、２４時間攪拌し、大気中にてそれぞれ３５０℃で２４時間熱処理を行った。遊星ミルで攪拌する際、直径１０ｍｍのボール５個と直径３ｍｍのボールを合計で１００ｇになるように加えた。
(Synthesis of Ti-doped sample)
The starting materials are lithium carbonate (Li 2 CO 3 , Wako 98%) as a lithium source, manganese powder (Mn, Wako 98%) as a manganese source, and titanium isopropoxide (Ti [(CH 3 ) 2 CHO] 4 as a Ti source. , Wako 95%), diphosphorus pentoxide (P 2 O 5 , Wako 98%) as a phosphorus source was weighed to a stoichiometric ratio in a glove box (10 g in total). Thereafter, excess pure water (50 ml) was added in the draft, and the mixture was stirred for 2 days using a magnetic stirrer to cause a reaction. Thereafter, in order to complete the reaction, the mixture was stirred for 24 hours at 200 rpm in a planetary mill (Planet Mill LP4 / 2 manufactured by Ito Seisakusho), and heat-treated at 350 ° C. for 24 hours in the atmosphere. When stirring with a planetary mill, 5 balls with a diameter of 10 mm and 3 mm with a diameter were added to a total of 100 g.
（カルボサーマル処理）
上記で得られた粉末試料はアセチレンブラックと７０：２５の重量比にて秤量し、遊星ミルにて乾式で２００ｒｐｍ、２４時間カーボンコート処理を行った。その後得られた炭素複合体試料をアルゴン雰囲気中にて５５０℃、１時間熱処理を行った。このようなカルボサーマル処理により得られた試料と結着剤であるポリテトラフルオロエチレンを９５：５の重量比で加え、メノウ乳鉢で混錬した後、コルクボーラーを用いて直径１．０ｃｍ、厚さ0.25ｍｍ厚のディスク状に型抜きし、これを正極ペレットとして使用した。
(Carbothermal treatment)
The powder sample obtained above was weighed with acetylene black at a weight ratio of 70:25, and subjected to carbon coating treatment in a planetary mill at 200 rpm for 24 hours. Thereafter, the obtained carbon composite sample was heat-treated at 550 ° C. for 1 hour in an argon atmosphere. A sample obtained by such carbothermal treatment and polytetrafluoroethylene as a binder were added at a weight ratio of 95: 5, kneaded in an agate mortar, and then 1.0 cm in diameter and thick using a cork borer. A disk was cut into a 0.25 mm thick disk and used as a positive electrode pellet.
（コインセルの作製）
上記正極ペレットを用いてコインセルを作製した。正極ペレットの対極として、直径１．５ｍｍ、厚さ０．１５ｍｍのリチウム箔を用いた。セパレータとしては、直径２２ｍｍ、厚さ０．０２ｍｍの多孔質ポリエチレンシートを用いた。非水電解質溶液としては、エチレンカーボネート（ＥＣ）とジメチルカーボネート（ＤＭＣ）との体積比１：１の混合溶媒に、約１モル／リットルの濃度でＬｉＰＦ６を溶解させたものを使用した。これらの構成要素をステンレス製の正極容器及び負極蓋に組み込んで、ガスケットで密封して、厚さ２ｍｍ、直径３２ｍｍ（２０３２型）の図２１に示すコイン型測定用セルを作製した。なお、一連の電池組み立て作業はアルゴン精製装置を備えた露点−９０℃以下のドライボックス内で行った。
(Production of coin cell)
A coin cell was produced using the positive electrode pellet. As the counter electrode of the positive electrode pellet, a lithium foil having a diameter of 1.5 mm and a thickness of 0.15 mm was used. As the separator, a porous polyethylene sheet having a diameter of 22 mm and a thickness of 0.02 mm was used. As the nonaqueous electrolyte solution, a solution obtained by dissolving LiPF 6 at a concentration of about 1 mol / liter in a mixed solvent of ethylene carbonate (EC) and dimethyl carbonate (DMC) in a volume ratio of 1: 1 was used. These components were incorporated into a stainless steel positive electrode container and a negative electrode lid and sealed with a gasket to produce a coin-type measurement cell shown in FIG. 21 having a thickness of 2 mm and a diameter of 32 mm (2032 type). In addition, a series of battery assembly operations were performed in a dry box having a dew point of −90 ° C. or less equipped with an argon purification device.
（充放電試験の方法）
充電は、４．５Ｖまでは電流密度０．１ｍＡ／ｃｍ２の定電流で行い、４．５Ｖ到達後は、４．５Ｖを維持し、電流密度が１桁小さい０．０１ｍＡ／ｃｍ２もしくは、充電容量が理論容量である１７０ｍＡｈ／ｇに到達時点を充電終了とした。放電は、２．０Ｖまで０．１−５．０ｍＡ／ｃｍ２のさまざまな電流密度で行った。
(Method of charge / discharge test)
Charging is performed at a constant current of a current density of 0.1 mA / cm 2 up to 4.5 V, and after reaching 4.5 V, the voltage is maintained at 4.5 V and the current density is 0.01 mA / cm 2 smaller by one digit, or When the charge capacity reached 170 mAh / g, which is the theoretical capacity, the charge was terminated. The discharge was performed at various current densities from 0.1 to 5.0 mA / cm 2 up to 2.0V.
（粒子径の測定方法）
正極活物質の粒子形状については、FE-SEM（JEOL JSM-6340F）にて観察し、粒度分布と平均粒径については、レーザー回折式粒度分布測定装置（Horiba LB-500X）にて測定した。
(Measurement method of particle diameter)
The particle shape of the positive electrode active material was observed with FE-SEM (JEOL JSM-6340F), and the particle size distribution and average particle size were measured with a laser diffraction particle size distribution analyzer (Horiba LB-500X).
２．実験結果及び評価
（合成試料の同定）
得られた試料は粉末Ｘ回折装置（Rigaku RINT2100HLR/PC）にて行った。図１にＭｇドープを行ったＬｉＭｎ１−ｘＭｇｘＰＯ４試料のＸＲＤプロファイルを示す。原子吸光測定によりＭｇ量が仕込み比どおり確認できており、ＸＲＤ測定の結果からは、Ｍｇドープを行ったことによる新たな不純物相は認められず、未ドープ試料同様オリビン型ＬｉＭｎＰＯ４（ＩＣＤＤ ３３−０８０４）の単相と同定された。図２にＭｇドープによる格子定数変化を示す。Ｍｇドープ量が増加するに従って、格子定数が減少しており、各ドープ量での格子定数はＬｉＭｎＰＯ４とＬｉＭｇＰＯ４（ＩＣＤＤ ３２−０５７４）の２点を結んだ直線上に存在することが確認できた。この結果から、ドーパントであるＭｇはＬｉＭｎＰＯ４結晶構造内、特にＭｎサイトに置換されて存在していると考えられる。図３にＴｉドープ試料を行った試料のＸＲＤプロファイルを示す。ＸＲＤ測定の結果からは、図１と同様にＴｉドープを行ったことによる新たな不純物相は認められず、未ドープ試料同様オリビン型ＬｉＭｎＰＯ４（ＩＣＤＤ ３３−０８０４）の単相と同定された。また、原子吸光測定によりＴｉ量が仕込み比どおり確認できており、ＸＲＤ測定により新たな不純物相が確認できていないことを併せると、ＴｉはＬｉＭｎＰＯ４結晶構造内に固溶していると考えられる。
2. Experimental results and evaluation (identification of synthetic samples)
The obtained sample was subjected to a powder X diffraction apparatus (Rigaku RINT2100HLR / PC). FIG. 1 shows an XRD profile of a LiMn 1-x Mg x PO 4 sample subjected to Mg doping. The amount of Mg was confirmed by atomic absorption measurement according to the charge ratio, and from the results of XRD measurement, no new impurity phase due to Mg doping was observed, and olivine-type LiMnPO 4 (ICDD 33- 0804) as a single phase. FIG. 2 shows changes in lattice constant due to Mg doping. As the Mg doping amount increases, the lattice constant decreases, and it can be confirmed that the lattice constant at each doping amount exists on a straight line connecting two points of LiMnPO 4 and LiMgPO 4 (ICDD 32-0574). It was. From this result, it is considered that Mg as a dopant is present in the LiMnPO 4 crystal structure, in particular, by being substituted with a Mn site. FIG. 3 shows an XRD profile of a sample subjected to the Ti-doped sample. From the results of the XRD measurement, a new impurity phase due to Ti doping was not recognized as in FIG. 1, and it was identified as a single phase of olivine type LiMnPO 4 (ICDD 33-0804) as in the undoped sample. In addition, it is considered that Ti is solid-solved in the LiMnPO 4 crystal structure, together with the fact that the amount of Ti can be confirmed according to the preparation ratio by atomic absorption measurement and the new impurity phase cannot be confirmed by XRD measurement. .
合成試料の粒子径を調べるために、ＦＥ−ＳＥＭ観察を行った。図４にＬｉＭｎ１−ｘＭｇｘＰＯ４試料のＳＥＭ写真を示す。得られた各試料の一次粒子径は１００−３００ｎｍの均一な微粒子であり、Ｍｇドープを行ったことによる粒子成長の促進は認められなかった。図５にＬｉＭｎ１−ｘＴｉｘＰＯ４試料のＳＥＭ写真を示す。Ｔｉドープ試料もＭｇドープ試料と同様に粒子成長の促進は確認できなかった。 In order to examine the particle size of the synthetic sample, FE-SEM observation was performed. FIG. 4 shows an SEM photograph of the LiMn 1-x Mg x PO 4 sample. The primary particle size of each of the obtained samples was uniform fine particles of 100 to 300 nm, and no promotion of particle growth due to Mg doping was observed. FIG. 5 shows an SEM photograph of the LiMn 1-x Ti x PO 4 sample. Similar to the Mg-doped sample, the Ti-doped sample could not confirm the promotion of particle growth.
これらの結果より、遊星ミルを用いた湿式法がナノサイズＬｉＭｎＰＯ４の合成だけでなく、ＭｇドープおよびＴｉドープを行ったナノサイズＬｉＭｎ１−ｘＭｘＰＯ４（Ｍ＝Ｍｇ、Ｔｉ）固溶体の合成も可能であることがわかった。 From these results, the wet method using a planetary mill not only synthesizes nano-sized LiMnPO 4 but also Mg-doped and Ti-doped nano-sized LiMn 1-x M x PO 4 (M = Mg, Ti) solid solution. It was found that synthesis is also possible.
（充放電試験の結果）
図６〜図９に各ＬｉＭｎ１−ｘＭｇｘＰＯ４試料の１サイクル目および２サイクル目の充放電プロファイルを示す。これらのプロファイルから、Ｍｇ１％、５％、１０％ドープ試料は未ドープ試料に比べ放電容量が２〜１０ｍＡｈ／ｇ程度増加しており、さらにＬｉＭｎＰＯ４特有の４．０Ｖ平坦部もより明瞭に確認することができた。図１０に各ＬｉＭｎ１−ｘＭｇｘＰＯ４試料のレート特性を示す。特にＭｇ１％ドープ試料は顕著に未ドープ試料よりもレート特性が改善されており、２．０ｍＡ／ｃｍ２で１２５ｍＡｈ／ｇ、３．０ｍＡ／ｃｍ２でも１１５ｍＡｈ／ｇであり、０．１ｍＡ／ｃｍ２放電容量と比較しても依然８０％以上維持できることがわかった。未ドープ試料と比較すると、２．０ｍＡ／ｃｍ２で２０％、３．０ｍＡ／ｃｍ２では８０％大きな容量を示した。これらの結果から、Ｍｇを特に１−５ ％程度ドープすることはＬｉＭｎＰＯ４のレート特性に有効であることがわかった。同様なことはＴｉドープ試料についても確認できた（図１１）。
(Result of charge / discharge test)
FIGS. 6 to 9 show charge / discharge profiles of the first and second cycles of each LiMn 1-x Mg x PO 4 sample. From these profiles, the Mg 1%, 5%, and 10% doped samples have a discharge capacity increased by about 2 to 10 mAh / g compared to the undoped samples, and the 4.0 V flat part peculiar to LiMnPO 4 is more clearly confirmed. We were able to. FIG. 10 shows the rate characteristics of each LiMn 1-x Mg x PO 4 sample. Particularly Mg1% doped sample is significantly improved rate characteristics than the undoped sample, it was at 2.0mA / cm 2 125mAh / g, 3.0mA / cm 2 , even 115mAh / g, 0.1mA / cm It was found that 80% or more can still be maintained even when compared with the two discharge capacities. Compared to undoped sample, 20% 2.0 mA / cm 2, showed a 80% greater capacity in 3.0 mA / cm 2. From these results, it was found that doping about 1 to 5% of Mg in particular is effective for the rate characteristics of LiMnPO 4 . The same was confirmed for the Ti-doped sample (FIG. 11).
図１２にＭｇ１％ドープ試料、Ｔｉ１％ドープ試料、未ドープ試料それぞれのレート特性を示す。Ｍｇ１％ドープ試料及びＴｉ１％ドープ試料のいずれにおいても２．０ｍＡ／ｃｍ２以上の高レートで特性改善が確認できた。図１３にこれらの試料のエネルギー密度を示す。ここでＬｉＦｅＰＯ４はＬｉＭｎＰＯ４と同等の１００−３００ｎｍの試料を用いた。本来、ＬｉＭｎＰＯ４はＬｉＦｅＰＯ４に比べ、電子伝導性が圧倒的に悪いにも関わらず、Ｍｇ１％ドープすることにより、２．０ｍＡ／ｃｍ２というハイレート下においてもＬｉＦｅＰＯ４に匹敵するエネルギー密度が得られるまでに特性改善が可能であることがわかった。 FIG. 12 shows the rate characteristics of the Mg 1% doped sample, the Ti 1% doped sample, and the undoped sample. In both the Mg 1% doped sample and the Ti 1% doped sample, improvement in characteristics was confirmed at a high rate of 2.0 mA / cm 2 or more. FIG. 13 shows the energy density of these samples. Here, a sample of 100 to 300 nm equivalent to LiMnPO 4 was used as LiFePO 4 . Originally, LiMnPO 4 is overwhelmingly poorer in electron conductivity than LiFePO 4 , but by doping with Mg 1%, an energy density comparable to LiFePO 4 can be obtained even at a high rate of 2.0 mA / cm 2. It was found that the characteristics could be improved before
図１４〜図１７に得られた試料のサイクル特性及び放電プロファイルを示す。 14 to 17 show the cycle characteristics and discharge profiles of the obtained samples.
本発明の正極活物質を利用した非水電解質電池としては、例えば、金属リチウム電池、リチウムイオン電池、リチウムポリマー電池等のリチウム二次電池が挙げられる。このような二次電池は特に電気自動車等の充電可能な電源として有用である。 Examples of the nonaqueous electrolyte battery using the positive electrode active material of the present invention include lithium secondary batteries such as metal lithium batteries, lithium ion batteries, and lithium polymer batteries. Such a secondary battery is particularly useful as a rechargeable power source for an electric vehicle or the like.
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006317795A JP5268042B2 (en) | 2006-11-24 | 2006-11-24 | Method for producing positive electrode active material and non-aqueous electrolyte battery using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006317795A JP5268042B2 (en) | 2006-11-24 | 2006-11-24 | Method for producing positive electrode active material and non-aqueous electrolyte battery using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2008130525A JP2008130525A (en) | 2008-06-05 |
| JP5268042B2 true JP5268042B2 (en) | 2013-08-21 |
Family
ID=39556133
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006317795A Active JP5268042B2 (en) | 2006-11-24 | 2006-11-24 | Method for producing positive electrode active material and non-aqueous electrolyte battery using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5268042B2 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5376399B2 (en) * | 2009-06-12 | 2013-12-25 | 株式会社Ｇｓユアサ | Positive electrode active material for lithium secondary battery and lithium secondary battery |
| US9225022B2 (en) | 2009-06-24 | 2015-12-29 | Gs Yuasa International Ltd. | Positive active material for lithium secondary battery and lithium secondary battery |
| JP5532350B2 (en) | 2009-12-15 | 2014-06-25 | トヨタ自動車株式会社 | Method for producing positive electrode active material for lithium secondary battery |
| JP5604962B2 (en) * | 2010-04-28 | 2014-10-15 | 株式会社Ｇｓユアサ | Positive electrode active material for secondary battery and secondary battery |
| US9985277B2 (en) * | 2010-10-20 | 2018-05-29 | Council Of Scientific & Industrial Research | Process for the preparation of high voltage nano composite cathode (4.9vV) for lithium ion batteries |
| JP5721171B2 (en) * | 2011-02-21 | 2015-05-20 | 国立大学法人九州大学 | Electrode active material and method for producing the same |
| JP2012204079A (en) * | 2011-03-24 | 2012-10-22 | Nichia Chem Ind Ltd | Olivine-type lithium transition metal oxide and method for producing the same |
| CN102306770A (en) * | 2011-08-15 | 2012-01-04 | 青岛乾运高科新材料有限公司 | Method for preparing solid-phase synthesis metal ion molybdenum-doped lithium ion phosphate serving as cathode material |
| WO2013133369A1 (en) | 2012-03-09 | 2013-09-12 | 国立大学法人長岡技術科学大学 | Cathode active material for sodium secondary battery and method for manufacturing the cathode active material for sodium secondary battery |
| US9388045B2 (en) | 2013-05-08 | 2016-07-12 | Changs Ascending Enterprise Co. | Synthesis and characterization of lithium nickel manganese cobalt phosphorous oxide |
| CA3002650C (en) * | 2014-07-24 | 2022-04-12 | Changs Ascending Enterprise Co., Ltd. | Synthesis and characterization of lithium nickel manganese cobalt phosphorous oxide |
| CN105161755B (en) * | 2015-09-01 | 2017-11-10 | 长兴天宏锂电科技有限公司 | A kind of environment-friendly type can large current density polymer battery preparation method |
| CN116830314B (en) * | 2022-04-01 | 2024-08-09 | 宁德时代新能源科技股份有限公司 | Secondary battery, battery module, battery pack, and power consumption device |
| CN118160112A (en) * | 2022-06-24 | 2024-06-07 | 宁德时代新能源科技股份有限公司 | Positive electrode material composition, preparation method thereof, positive electrode sheet comprising positive electrode material composition, secondary battery and electric device |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4491950B2 (en) * | 2000-10-06 | 2010-06-30 | ソニー株式会社 | Method for producing positive electrode active material and method for producing non-aqueous electrolyte battery |
| CA2455540C (en) * | 2002-12-19 | 2012-08-28 | Valence Technology, Inc. | Electrode active material and method of making the same |
| JP4794833B2 (en) * | 2004-07-21 | 2011-10-19 | 日本コークス工業株式会社 | Positive electrode material for lithium ion secondary battery, method for producing the same, and lithium ion secondary battery |
| JP4959145B2 (en) * | 2005-03-30 | 2012-06-20 | 日本碍子株式会社 | Positive electrode for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery |
| JP4655721B2 (en) * | 2005-03-31 | 2011-03-23 | 株式会社日立製作所 | Lithium ion secondary battery and positive electrode active material |
-
2006
- 2006-11-24 JP JP2006317795A patent/JP5268042B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2008130525A (en) | 2008-06-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5268042B2 (en) | Method for producing positive electrode active material and non-aqueous electrolyte battery using the same | |
| JP5268134B2 (en) | Method for producing positive electrode active material and non-aqueous electrolyte battery using the same | |
| TWI403458B (en) | Method for preparing lithium metal phosphate | |
| EP2737565B1 (en) | Blended cathode materials | |
| JP4058680B2 (en) | Method for producing positive electrode active material and method for producing non-aqueous electrolyte secondary battery | |
| KR101718054B1 (en) | Positive active material, and electrode and lithium battery containing the material | |
| KR101612566B1 (en) | Mixed metal olivine electrode materials for lithium ion batteries | |
| JP5235282B2 (en) | Cathode active material and battery for non-aqueous electrolyte secondary battery | |
| JP4641375B2 (en) | Method for producing composite of olivine type lithium phosphate and carbon material | |
| JP5314258B2 (en) | Olivine-type lithium iron phosphate compound and method for producing the same, and positive electrode active material and non-aqueous electrolyte battery using olivine-type lithium iron phosphate compound | |
| JP5463561B2 (en) | COMPOUND HAVING ORIBIN STRUCTURE, PROCESS FOR PRODUCING THE SAME, POSITIVE ACTIVE MATERIAL USING COMPOUND HAVING ORIBIN STRUCTURE AND NON-AQUEOUS ELECTROLYTE BATTERY | |
| JP5684915B2 (en) | Anode active material for lithium secondary battery, method for producing the same, and lithium secondary battery including the same | |
| KR101555932B1 (en) | Electrode active material for lithium secondary battery and Method of preparing the same | |
| JP2002117833A (en) | Nonaqueous electrolyte secondary battery | |
| KR20140108102A (en) | Composite positive active material and manufacturing method thereof, positive electrode and lithium battery containing the material | |
| US9570743B2 (en) | Positive active material precursor for rechargeable lithium battery, method of preparing positive active material for rechargeable lithium battery using the same, and rechargeable lithium battery including the prepared positive active material for rechargeable lithium battery | |
| KR101186686B1 (en) | Method of preparing positive active material for rechargeable lithium battery | |
| KR20160080865A (en) | Positive active material and manufacturing method thereof, positive electrode and lithium battery containing the material | |
| JP4491947B2 (en) | Method for producing positive electrode active material and method for producing non-aqueous electrolyte battery | |
| JP6197540B2 (en) | Positive electrode material for lithium ion secondary battery, positive electrode for lithium ion secondary battery and lithium ion secondary battery | |
| JP5598684B2 (en) | Positive electrode active material for non-aqueous electrolyte secondary battery, positive electrode and battery | |
| CN108630938B (en) | Positive electrode active material, positive electrode using same, and lithium ion secondary battery | |
| KR101631736B1 (en) | Lithium manganese phosphate based anode active material, preparation method thereof, and lithium secondary battery or hybrid capacitor comprising the same | |
| WO2016021068A1 (en) | Method for producing lithium composite metal phosphate compound, method for producing olivine-type lithium iron phosphate, olivine-type lithium iron phosphate, and secondary battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20091120 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20110912 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20120601 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120605 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120802 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120903 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20121102 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20130402 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20130430 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5268042 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |