Gs Yuasa International Ltd.

Gs Yuasa Corporation

Yoshihiro Katayama

Toshiyuki Nukuda

Daisuke Endo

Shigeki Yamate

Suguru Kozono

Miki Yasutomi

Takeshi Sasaki

Tokuo Inamasu

Tetsuya Murai

Naohiro Tsumura

Ichiro Tanaka

Masafumi Shibata

Taro Yamafuku

Atsushi Funabiki

Kazusa Ohkubo

Koji Sukino

Kazusa Yukimoto

An object of the present invention is to provide a positive active material for a nonaqueous electrolyte secondary battery which has a large discharge capacity and is superior in charge-discharge cycle performance, initial efficiency and high rate discharge performance, and a nonaqueous electrolyte secondary battery using the positive active material. The present invention pertains to a positive active material for a nonaqueous electrolyte secondary battery containing a lithium transition metal composite oxide which has a crystal structure of an &#x3b1;-NaFeOtype, is represented by a compositional formula LiMeO(Me is a transition metal element including Co, Ni and Mn, &#x3b1;&#x3e;0), and has a molar ratio Li/Me of Li to the transition metal element Me of 1.2 to 1.6, wherein a molar ratio Co/Me of Co in the transition metal element Me is 0.02 to 0.23, a molar ratio Mn/Me of Mn in the transition metal element Me is 0.62 to 0.72, and the lithium transition metal composite oxide is observed as a single phase attributed to a space group R3-m on an X-ray diffraction chart when it is electrochemically oxidized up to a potential of 5.0 V (vs. Li/Li).

Positive active material for nonaqueous electrolyte secondary battery, method of manufacturing the positive active material, electrode for nonaqueous electrolyte secondary battery, nonaqueous electrolyte secondary battery and method of manufacturing the secondary battery

A lithium secondary battery is produced by employing a charging method where a positive electrode upon charging has a maximum achieved potential of 4.3 V (vs. Li/Li) or lower. The lithium secondary battery contains an active material including a solid solution of a lithium transition metal composite oxide having an &#x3b1;-NaFeO-type crystal structure. The solid solution has a diffraction peak observed near 20 to 30&#xb0; in X-ray diffractometry using CuK&#x3b1; radiation for a monoclinic Li[LiMn]O-type before charge-discharge. The lithium secondary battery is charged to reach at least a region with substantially flat fluctuation of potential appearing in a positive electrode potential region exceeding 4.3 V (vs. Li/Li) and 4.8 V (vs. Li/Li) or lower. A dischargeable electric quantity in a potential region of 4.3 V (vs. Li/Li) or lower is 177 mAh/g or higher.

Method for producing active material for lithium secondary battery and method of using lithium secondary battery

An electric storage device includes a negative electrode, a positive electrode, and a separator interposed between the negative electrode and the positive electrode, the negative electrode including a negative electrode layer including an active material including an amorphous carbon particle capable of occluding and releasing at least one of an alkali metal and an alkaline earth metal, and a binder. The negative electrode layer includes a plurality of pores, and a ratio S/Sof a specific surface area (S) of micropores having a pore diameter of 1 nm or more and 3 nm or less in the pores to a specific surface area (S) of mesopores having a pore diameter of 20 nm or more and 100 nm or less therein is 0.3 or more and 0.9 or less.

Electric storage device

[Object]; There is provided an active material for a lithium secondary battery, which has a high initial efficiency and a high discharge capacity, and particularly has a high discharge capacity at a low temperature (excellent low-temperature characteristic), and a lithium secondary battery using the active material. [Solution]; An active material for a lithium secondary battery, which contains a solid solution of a lithium transition metal composite oxide having an &#x3b1;-NaFeOcrystal structure, wherein the composition ratio of metal elements contained in the solid solution satisfies, LiNaCoNiMnO(0&#x3c;y&#x2266;0.1, 0.4&#x2266;c&#x2266;0.7, x+a+b+c=1, 0.1&#x2266;x&#x2266;0.25, &#x2212;0.2&#x2266;d&#x2266;0.2), the active material has an X-ray diffraction pattern attributable to a space group R3-m (P312), and in the Miller index hkl, the half width of the diffraction peak of the (003) is 0.30&#xb0; or less and the half width of the diffraction peak of the (114) plane is 0.50&#xb0; or less. Further, the average of three oxygen position parameters determined from crystal structure analysis by the Rietveld method on the basis of the X-ray diffraction pattern is preferably 0.264 or less.

Active material for lithium secondary battery, electrode for lithium secondary battery, and lithium secondary battery

An object of the present invention is to provide a negative electrode, an electrode assembly and an electric storage device. The negative electrode has a negative electrode layer containing: an active material containing an amorphous carbon particle capable of occluding and releasing at least one of an alkali metal and an alkaline earth metal; and a binder, the negative electrode layer having a plurality of pores; and the ratio S/Sof the specific surface area (S) of micropores having a pore diameter of 1 nm or larger and 3 nm or smaller in the pores to the specific surface area (S) of mesopores having a pore diameter of 20 nm or larger and 100 nm or smaller therein being 0.3 or higher and 0.9 or lower.

Negative electrode, electrode assembly and electric storage device

It is an object of the present invention to provide an active material for a lithium secondary battery having high discharge capacity and excellent in high rate discharge characteristics and a lithium secondary battery using the same. The active material for a lithium secondary battery containing a solid solution of a lithium-transition metal composite oxide having an &#x3b1;-NaFeOtype crystal structure and the lithium secondary battery using the same have features that the composition ratios of the metal elements contained in the solid solution satisfy LiCoNiMgMn(x&#x3e;0; y&#x3e;0; z&#x3e;0; x+y+z&#x3c;1); the active material has an X-ray diffraction pattern capable of belonging to space group P; and the active material has discharge capacity exceeding 200 mAh/g. Further, in addition to the above-mentioned features, they have features that an intensity ratio between the diffraction peak of (003) plane and the diffraction peak of (114) plane measured by X-ray diffractometry is I/I&#x2267;1.15 and/or the half width of the diffraction peak of (003) plane is 0.15&#xb0; or less and the half width of the diffraction peak of (114) plane is 0.25&#xb0; or less.

Active material for lithium secondary battery, electrode for lithium secondary battery, lithium secondary battery, and method for producing the same

The active material for a lithium secondary battery includes a solid solution of a lithium transition metal composite oxide having an &#x3b1;-NaFeOtype crystal structure, in which the composition ratio of Li, Co, Ni, and Mn contained in the solid solution satisfies LiCoNiMn(x+y&#x2266;1, 0&#x2266;y and 1&#x2212;x&#x2212;y=z); in an Li[LiMn]O(x)-LiNiMnO(y)-LiCoO(z) type ternary phase diagram, (x, y, z) is represented by values in a range present on or within a line of a heptagon (ABCDEFG) defined by the vertexes; point A(0.45, 0.55, 0), point B(0.63, 0.37, 0), point C(0.7, 0.25, 0.05), point D(0.67, 0.18, 0.15), point E(0.75, 0, 0.25), point F(0.55, 0, 0.45), and point G(0.45, 0.2, 0.35); and the intensity ratio between the diffraction peaks on (003) plane and (104) plane measured by X-ray diffractometry before charge-discharge is I/I&#x2267;1.56 and at the end of discharge is I/I&#x3e;1.

Active material for lithium secondary battery, lithium secondary battery, and method for producing the same

An additive typified by tris(trimethylsilyl)phosphate, tris(trimethylsilyl)borate, and tetrakis(trimethylsiloxy)titanium (Chem. 3) are applied to a nonaqueous electrolyte containing a chain carbonate and/or a chain carboxylate as a main solvent (contained at a ratio of 70 volume % or higher). It is preferable that 0&#x2266;a&#x3c;30 is satisfied, in which 'a' denotes the volume of a cyclic carbonate among carbonates having no carbon-carbon double bond in the entire volume, defined as 100, of the carbonates having no carbon-carbon double bond and chain carboxylates in a nonaqueous solvent contained in the nonaqueous electrolyte (0&#x3c;a&#x3c;30 in the case no chain carboxylate is contained).

Nonaqueous electrolyte battery

A process for producing a lithium secondary battery employs a charging method where a positive electrode upon charging has a maximum achieved potential of 4.3 V (vs. Li/Li+) or lower. The process includes charging the lithium secondary battery to reach at least a region with relatively flat fluctuation of potential appearing in a positive electrode potential region exceeding 4.3 V (vs. Li/Li) and 4.8V (vs. Li/Li) or lower. The lithium secondary battery includes an active material having a solid solution of a lithium transition metal composite oxide having an &#x3b1;-NaFeOtype crystal structure. The composition ratio of Li, Co, Ni, and Mn contained in the solid solution satisfies LiCoNiMn(x+y&#x2266;1, 0&#x2266;y and 1&#x2212;x&#x2212;y=z).

Process for producing lithium secondary battery

Gas generation of a non-aqueous electrolyte battery having a negative active material that intercalates/deintercalates lithium ions at a potential not lower than 1.2 V relative to the potential of lithium as negative electrode is suppressed. A non-aqueous electrolyte battery comprising a non-aqueous electrolyte containing an electrolyte salt and a non-aqueous solvent, a positive electrode and a negative electrode is characterized in that the main active material of said negative electrode is an active material that intercalates/deintercalates lithium ions at a potential not lower than 1.2 V relative to the potential of lithium and the auxiliary active material of said negative electrode is an active material that at least intercalates lithium ions at a potential lower than 1.2 V relative to the potential of lithium and that there exists lithium showing a spin-lattice relaxation time (T) of not less than 1 second as determined by a solid-state Li&#x2014;NMR measurement in the main active material of said negative electrode. A method of manufacturing a non-aqueous electrolyte battery containing a non-aqueous electrolyte, a positive electrode and a negative electrode (a main active material and an auxiliary active material of the negative electrode) is characterized in that the negative electrode potential is lowered to not higher than 0.8 V relative to the potential of lithium at least once in the initial cycle.

Non-aqueous electrolyte battery and method of manufacturing the same

A non-aqueous electrolyte battery includes a non-aqueous electrolyte containing an electrolytic salt and a non-aqueous solvent, a positive electrode, and a negative electrode having a negative active material that intercalates/deintercalates lithium ions at a potential not lower than 1.2 V relative to the potential of lithium, wherein a film coat having a carbonate structure and a thickness of not less than 10 nm exists on the surface of the negative electrode. A non-aqueous electrolyte battery is operated in a region of potential of the negative electrode higher than 0.8 V relative to the potential of lithium.

Non-aqueous electrolyte battery, method of manufacturing the same and method of using the same

It is an object of the present invention to provide an active material for lithium ion battery having an excellent discharge capacity in the potential flat part and a high-performance and long-life lithium ion battery, and particularly to provide a technology of improving voltage flatness. The present invention provides an active material for lithium ion battery represented by a composition formula: Li[LiMgTi]O(0&#x3c;x&#x3c;1/2) in which a part of the element of lithium titanate is substituted with Mg, and a lithium ion battery using this active material as a negative electrode active material.

Active material for lithium ion battery having Mg-containing lithium titanate and lithium ion battery

It is an object of the present invention to provide an active material for lithium ion battery capable of producing a lithium ion battery having an excellent high rate charge and discharge performance and a lithium ion battery having an excellent high rate charge and discharge performance. The present invention provides an active material for lithium ion battery represented by a composition formula: Li[LiAlTi]O(&#x215b;&#x2266;x&#x3c;1) lithium titanate is substituted with Al, and a lithium ion battery using this active material as a negative electrode active material.

Active material for lithium ion battery having Al-containing lithium titanate and lithium ion battery

A nonaqueous electrolytic cell manufacturing method is characterized in that a nonaqueous electrolyte containing vinylene carbonate is used, a coating on the surface of the negative electrode is formed at the initial charging/discharging in such a way by lowering the negative electrode potential to less than 0.4 V with relative to the lithium potential, wherein the nonaqueous electrolytic cell comprises a nonaqueous electrolyte containing an electrolytic salt and a nonaqueous solvent, a positive electrode, and a negative electrode containing a negative electrode material into/from which lithium ions are inserted/desorbed at a potential higher than the lithium potential by 1.2 V. The nonaqueous electrolytic cell is used in a range of negative electrode potential nobler than the lithium potential by 0.8 V.

Growing community of inventors

Kyoto, Japan

Yoshihiro Katayama