Sumitomo Chemical Company, Limited

Tanaka Chemical Corporation

Daisuke Yamashita

Yuichiro Imanari

Kenji Takamori

Hiroyuki Kurita

Kimiyasu Nakao

Takaaki Masukawa

Yoshiyuki Koizumi

Jun-ichi Kageura

Yasutaka Iida

Hiroyuki Ito

Takao Mizuno

Takashi Arimura

Yusuke Maeda

Kyousuke Doumae

Noriyuki Shimada

A positive electrode active material for lithium secondary batteries which is able to doped/undoped with lithium ions and contains at least Ni, in which a ratio P/Q (atom %/mass %) of a concentration P (atom %) of sulfur atoms being present in a surface of the positive electrode active material to a concentration Q (mass %) of sulfuric acid radicals being present in the whole positive electrode active material is more than 0.8 and less than 5.0, and the Q (mass %) is 0.01 or more and 2.0 or less.

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

An object of the present invention is to provide a method for manufacturing methionine capable of achieving an improvement in ammonia removal efficiency. The manufacturing method of the present invention comprises a removal step of supplying a liquid containing a methionine salt, which is obtained by reacting 3-methylmercaptopropionaldehyde and hydrocyanic acid, or a compound obtained by reacting 3-methylmercaptopropionaldehyde and hydrocyanic acid, with carbon dioxide and ammonia to obtain a liquid containing 5-(2-methylmercaptoethyl)hydantoin and then hydrolyzing the 5-(2-methylmercaptoethyl)hydantoin, to a diffusion tower from an upper portion thereof while supplying a stripping gas to the diffusion tower from a lower portion thereof to remove ammonia contained in the liquid through stripping, and the stripping gas contains a process gas generated in a process of manufacturing methionine.

Method for manufacturing methionine

An object of the present invention to provide a method for producing methionine with consideration given to the environment. The production method of the present invention comprises a removal step of blowing an inert gas into a liquid containing 5-(2-methylmercaptoethyl)hydantoin and thereby diffusing ammonia remaining in the liquid to obtain an emission gas containing the ammonia, and a recovery step of bringing the emission gas into contact with a washing liquid to recover ammonia contained in the emission gas.

Method for producing methionine

An object of the present invention is to provide a method for producing methionine enabling efficient recovery and use of ammonia from a gas generated by concentrating a mother liquor. This production method comprises a recovery step of introducing a gas generated in a mother liquor concentration step into a gas washing tower in which water is recycled and bringing the gas into contact with the water to recover ammonia contained in the gas, and a ratio of flow of the water to flow of the gas introduced into the gas washing tower is 2 or more in terms of mass ratio. The water discharged from the gas washing tower is preferably cooled before introduction into the gas washing tower.

The object of the present invention is to provide a positive electrode active material usable for a lithium ion battery capable of high charge/discharge cycle performance and high discharge capacity. The positive electrode active material for a lithium secondary battery has a layered structure and comprises at least nickel, cobalt and manganese. Further, the positive electrode active material satisfies requirements (1) to (3) below: (1) a primary particle size of 0.1 &#x3bc;m to 1 &#x3bc;m, and a 50% cumulative particle size Dof 1 &#x3bc;m to 10 &#x3bc;m, (2) a ratio (D/D) of volume-based 90% cumulative particle size Dto volume-based 10% cumulative particle size Dof 2 to 6, and (3) a lithium carbonate content in a residual alkali on particle surfaces of 0.1% by mass to 0.8% by mass as measured by neutralization titration.

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

A positive electrode active material for a lithium secondary cell, having a layered structure and comprising at least nickel, cobalt and manganese, the positive electrode active material satisfying requirements (1), (2) and (3) below: (1) a composition represented by a composition formula: Li[Li(NiCoMnM)]O, wherein 0&#x2264;x&#x2264;0.10, 0.30&#x3c;&#x3b1;&#x2264;0.34, 0.30&#x3c;&#x3b2;&#x2264;0.34, 0.32&#x2264;&#x3b3;&#x3c;0.40, 0&#x2264;&#x3b4;&#x2264;0.10, &#x3b2;&#x3c;&#x3b3;, &#x3b4;+&#x3b1;+&#x3b2;+&#x3b3;=1, M represents at least one metal selected from the group consisting of Fe, Cu, Ti, Mg, Al, W, Zn, Sn, Zr, Ga and V; (2) a secondary particle diameter of 2 &#x3bc;m or more and 10 &#x3bc;m or less; and (3) a maximum peak value in a pore diameter range of 90 nm to 150 nm in a pore diameter distribution determined by mercury porosimetry.

Positive-electrode active material for lithium secondary cell, positive electrode for lithium secondary cell, and lithium secondary cell

A positive electrode active material, which has a crystallite size &#x3b1;/crystallite size &#x3b2; ratio (&#x3b1;/&#x3b2;) of 1 to 1.75 or less, wherein the crystallite size &#x3b1; is within a peak region of 2&#x3b8;=18.7&#xb1;1&#xb0; and the crystallite size &#x3b2; is within a peak region of 2&#x3b8;=44.6&#xb1;1&#xb0;, each determined by a powder X-ray diffraction measurement using Cu-K&#x3b1; ray, and has a composition represented by formula (I) below:Li[Li(NiCoMnM)]O&#x2003;&#x2003;(I)wherein 0&#x2264;x&#x2264;0.2, 0.3&#x3c;a&#x3c;0.7, 0&#x3c;b&#x3c;0.4, 0&#x3c;c&#x3c;0.4, 0&#x2264;d&#x3c;0.1, a+b+c+d=1, and M is at least one metal selected from the group consisting of Fe, Cr, Ti, Mg, Al and Zr.

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

Provided is a positive electrode active material which is useful for a lithium secondary battery having a battery resistance lower than that of the conventional positive electrode active material below freezing point. The positive electrode active material for a lithium secondary battery contains at least one element selected from a group consisting of nickel, cobalt and manganese, the positive electrode active material having a layered structure and satisfying all of the following requirements (1) to (3): (1) a primary particle size is 0.1 &#x3bc;m to 1 &#x3bc;m and a secondary particle size is 1 &#x3bc;m to 10 &#x3bc;m; (2) in an X-ray powder diffraction measurement using CuK&#x3b1; radiation, a crystallite size in the peak within 2&#x3b8;=18.7&#xb1;1&#xb0; is 100 &#x212b; to 1200 &#x212b; and a crystallite size in the peak within 2&#x3b8;=44.6&#xb1;1&#xb0; is 100 &#x212b; to 700 &#x212b;; and (3) in a pore distribution obtained by a mercury intrusion method, a pore peak exists in a range where the pore size is 10 nm to 200 nm and a pore volume in the said range is 0.01 cm/g to 0.05 cm/g.

Growing community of inventors

Fukui, Japan

Daisuke Yamashita