Toyota Jidosha Kabushiki Kaisha

Sumitomo Chemical Company, Limited

Tanaka Chemical Corporation

Tetsuri Nakayama

Kenji Takamori

Cedric Pitteloud

Kyousuke Doumae

Maiko Saka

Takashi Kitamoto

A positive electrode active material for a lithium secondary battery, comprising a lithium-containing composite metal oxide in the form of secondary particles formed by aggregation of primary particles capable of being doped and undoped with lithium ions, each of the secondary particles having on its surface a coating layer, the positive electrode active material satisfying the following requirements (1) to (3): (1) the metal oxide has an &#x3b1;-NaFeOtype crystal structure of following formula (A):Li(NiCoM)O&#x2003;&#x2003;(A)wherein 0.9&#x2264;a&#x2264;1.2, 0.9&#x2264;b&#x3c;1, 0&#x3c;c&#x2264;0.1, 0.9&#x3c;b+c&#x2264;1, and Mrepresents at least one optional metal selected from Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In and Sn; (2) the coating layer comprises Li and M, wherein Mrepresents at least one optional metal selected from Al, Ti, Zr and W; and (3) the active material has an average secondary particle diameter of 2 to 20 &#x3bc;m, a BET specific surface area of 0.1 to 2.5 m/g, and a value of 1.0 to 2.0 as a tamped density/untamped density ratio of the active material.

Positive electrode active material for lithium secondary batteries, positive electrode for lithium secondary batteries, and lithium secondary battery

A non-aqueous electrolyte secondary battery disclosed herein includes a positive electrode, a negative electrode, and a non-aqueous electrolyte. The positive electrode includes a positive electrode current collector, and a positive electrode active material layer, an insulating layer, and a boundary layer which are provided on the positive electrode current collector. The boundary layer is positioned between the positive electrode active material layer and the insulating layer, and is in contact with the positive electrode active material layer and the insulating layer. The positive electrode active material layer contains a positive electrode active material. The insulating layer contains an inorganic filler. The boundary layer contains the positive electrode active material contained in the positive electrode active material layer and the inorganic filler contained in the insulating layer. The boundary layer contains hydrated alumina. The non-aqueous electrolyte contains lithium fluorosulfonate.

Non-aqueous electrolyte secondary battery

Provided is a nonaqueous electrolyte secondary battery with excellent low-temperature performance. The nonaqueous electrolyte secondary battery disclosed herein includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a nonaqueous electrolytic solution. The positive electrode includes a positive electrode active material layer. The positive electrode active material layer includes, as a positive electrode active material, a lithium transition metal composite oxide including at least lithium, nickel, manganese, cobalt, and tungsten. The nonaqueous electrolytic solution includes lithium fluorosulfonate and LiPF. The concentration of LiPFin the nonaqueous electrolytic solution is 1.11 mol/L or more. The viscosity of the nonaqueous electrolytic solution at 25&#xb0; C. is 3.1 cP or more. The separator includes a resin layer and an inorganic layer formed on a surface of the resin layer that faces the positive electrode. Where a porosity of the inorganic layer is denoted by &#x3b1;, a porosity of the resin layer is denoted by &#x3b2;, and a porosity of the positive electrode active material layer is denoted by &#x3b3;, relationships of 0.6&#x2264;(&#x3b2;/&#x3b1;)&#x2264;0.9 and 0.6&#x2264;(&#x3b3;/&#x3b1;)&#x2264;0.9 are fulfilled.

Nonaqueous electrolyte secondary battery

Provided is a nonaqueous electrolyte secondary battery in which lithium fluorosulfonate is added to a nonaqueous electrolytic solution and which exhibits excellent low-temperature performance. The nonaqueous electrolyte secondary battery disclosed herein includes a positive electrode, a negative electrode, and a nonaqueous electrolytic solution. The positive electrode includes a positive electrode active material layer. The positive electrode active material layer includes trilithium phosphate and, as a positive electrode active material, a lithium transition metal composite oxide including at least lithium, nickel, manganese, and cobalt. The nonaqueous electrolytic solution includes lithium fluorosulfonate. A mass ratio of trilithium phosphate to the positive electrode active material is 1% by mass or more and 5% by mass or less. A content of lithium fluorosulfonate in the nonaqueous electrolytic solution is 0.15% by mass or more and 1.0% by mass or less.

Nonaqueous electrolyte secondary battery including trilithium phosphate and lithium fluorosulfonate

Provided is a nonaqueous electrolyte secondary battery in which lithium fluorosulfonate is added to a nonaqueous electrolytic solution and which demonstrates excellent low-temperature performance. The nonaqueous electrolyte secondary battery disclosed herein includes a positive electrode, a negative electrode, and a nonaqueous electrolytic solution. The positive electrode includes a positive electrode active material layer. The positive electrode active material layer includes, as a positive electrode active material, a lithium transition metal composite oxide including at least lithium, nickel, manganese, and cobalt. The nonaqueous electrolytic solution includes lithium fluorosulfonate. A dibutyl phthalate absorption amount of the positive electrode active material is 28 mL/100 g or more and 45 mL/100 g or less. A content of lithium fluorosulfonate in the nonaqueous electrolytic solution is 0.15% by mass or more and 1.0% by mass or less.

Nonaqueous electrolyte secondary battery including lithium fluorosulfonate

Provided is a positive electrode material for a nonaqueous electrolyte secondary battery that excels in thermal stability. A positive electrode material for a nonaqueous electrolyte secondary battery, which is provided by the present invention, includes positive electrode active material particles that can reversibly store and release a charge carrier, and a metal hydroxide. Each of the positive electrode active material particles has inside thereof a void and the metal hydroxide is disposed inside the void.

Positive electrode material for nonaqueous electrolyte secondary battery and manufacturing method thereof

Provided is a positive electrode material for a lithium secondary battery that excels in durability and has a high electron conductivity (typically, a low battery resistance). A positive electrode material for a lithium secondary battery, which is provided by the present invention, includes positive electrode active material particles that can reversibly store and release a charge carrier, and lithium phosphate. Each of the positive electrode active material particles has a hollow structure having a shell configured of primary particles and a hollow portion formed inside the shell. Lithium phosphate is disposed inside the hollow portion, and no lithium phosphate is disposed on the outer circumferential surface of each of the positive electrode active material particles.

Positive electrode material for lithium secondary battery and manufacturing method thereof

The present invention provides a positive electrode active material. The positive electrode active material is represented by the following formula (I) and has a BET specific surface area of larger than 5 m/g and not larger than 15 m/g:LiMMO&#x2003;&#x2003;(I)wherein Mis at least one transition metal element selected from Group 5 elements and Group 6 elements of the Periodic Table, Mis at least one transition metal element other than Mand selected from among transition metal elements excluding Fe, x is not less than 0.9 and not more than 1.3, and y is more than 0 and less than 1.

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Toyota, Japan

Tetsuri Nakayama