A combined processing method for the purification of lithium containing solutions, the method comprising the method steps of passing a lithium containing solution to a first purification step in which the lithium containing solution is contacted with a titanate adsorbent whereby lithium ions are adsorbed thereon whilst rejecting substantially all other cations, the recovery of lithium from the adsorbent providing a part-purified lithium containing solution, the part-purified lithium containing solution produced in the first purification step is then passed in whole or part to a second purification step in which a graphene based filter medium is utilised to provide a further purified lithium containing solution.

Provided is a particulate alkaline earth metal ion adsorbent having a large adsorption capacity. The particulate alkaline earth metal ion adsorbent comprising: a potassium hydrogen dititanate hydrate represented by a chemical formula K.sub.2-xH.sub.xO.2TiO.sub.2.nH.sub.2O, wherein x is 0.5 or more and 1.3 or less, and n is greater than 0; and no binder, wherein the particulate alkaline earth metal ion adsorbent has a particle size range of 150 m or more and 1000 m or less.

Provided is a friction material composition that can increase the coefficient of friction and the wear resistance, reduce the compressive deformation rate, and improve the yield upon hot forming, even when being free of copper component or having a small content of copper component. The friction material composition contains: titanate compound powder made of non-fibrous titanate compound particles; barium sulfate powder; and a thermosetting resin, wherein the titanate compound powder has an alkali metal ion dissolution rate of 15.0% by mass or less, the barium sulfate powder has a volume-based 50% cumulative particle diameter (D.sub.50) of 0.1 m to 20.0 m, and a content of copper component is 0.5% by mass or less in terms of copper element in a total amount of 100% by mass of the friction material composition.

An object of the present invention is to provide a lithium titanate powder and an active material which, in the case of being applied as an electrode material of an energy storage device, can suppress the gas generation at high temperatures and the capacity reduction in high-temperature charge and discharge cycles and besides can also suppress the resistance rise in the high-temperature charge and discharge cycles, an electrode sheet, of an energy storage device, containing these, and an energy storage device using the electrode sheet. The lithium titanate powder contains Li.sub.4Ti.sub.5O.sub.12 as a main component, wherein the powder contains secondary particles being aggregates of primary particles composed of lithium titanate, and has a D.sub.BET of 0.03 m or more and 0.6 m or less and a D50 of 3 m or more and 40 m or less where the D.sub.BET represents a specific surface area-equivalent diameter calculated from a specific surface area determined by a BET method, and the D50 represents a median particle diameter in volume, a ratio D50/D.sub.BET (m/m) of D50 to D.sub.BET of 20 or more and 350 or less, a moisture amount (25 C. to 350 C.) of 600 ppm or less as measured by Karl Fischer's method, and an average 10%-compressive strength of the secondary particles of 0.1 MPa or more and 3 MPa or less.

In general, according to one embodiment, there is provided an active material. The active material contains a composite oxide having an orthorhombic crystal structure. The composite oxide is represented by a general formula of Li.sub.2+wNa.sub.2xM1.sub.yTi.sub.6zM2.sub.zO.sub.14+. In the general formula, the M1 is at least one selected from the group consisting of Cs and K; the M2 is at least one selected from the group consisting of Zr, Sn, V, Nb, Ta, Mo, W, Fe, Co, Mn, and Al; and w is within a range of 0w4, x is within a range of 0<x<2, y is within a range of 0y<2, z is within a range of 0<z6, and is within a range of 0.50.5.

An objective of the present disclosure is to provide a method of producing metal compound particle group for an electricity storage device electrode that has an improved rate characteristic, the metal compound particle group, and an electrode formed of the metal compound particle group. The method of producing metal compound particle group applied for an electrode of an electricity storage device, the method includes a step of combining a precursor of metal compound particle with a carbon source to obtain a first composite material, a step of producing the metal compound particle by heat processing the first composite material under a non-oxidizing atmosphere to obtain a second composite material having the metal compound particle combined with carbon, and a step of eliminating carbon by heat processing the second composite material under an oxygen atmosphere to obtain the metal compound particle group having the metal compound particle coupled in a three-dimensional mesh structure.

An active material particle according to an aspect of the present invention contains an active material base material and a covering layer covering at least a part of a surface of the active material base material, the covering layer contains an oxide containing lithium atoms and titanium atoms, and a molar ratio of a content of the lithium atoms to the titanium atoms in the oxide is more than 1 and 4 or less.

The present invention provides a particulate cobalt ion adsorbent which has a high adsorption capacity. A particulate cobalt ion adsorbent which contains potassium hydrogen dititanate hydrate represented by chemical formula K.sub.2-XH.sub.xO.2TiO.sub.2.nH.sub.2O (wherein x is 0.5 or more and 1.3 or less, and n is greater than 0), and no binder, wherein the particulate cobalt ion adsorbent has a particle size range of 150 m or more and 1000 m or less.

An objective of the present disclosure is to provide a method of producing metal compound particle group for an electricity storage device electrode that has an improved rate characteristic, the metal compound particle group, and an electrode formed of the metal compound particle group. The method of producing metal compound particle group applied for an electrode of an electricity storage device, the method includes a step of combining a precursor of metal compound particle with a carbon source to obtain a first composite material, a step of producing the metal compound particle by heat processing the first composite material under a non-oxidizing atmosphere to obtain a second composite material having the metal compound particle combined with carbon, and a step of eliminating carbon by heat processing the second composite material under an oxygen atmosphere to obtain the metal compound particle group having the metal compound particle coupled in a three-dimensional mesh structure.

Provided are novel titanium oxide particles, production method thereof, and applications which do not need a conductive aid or minimize the conductive aid. Novel titanium oxide particles 1 employ a three-dimensional network structure in which multiple crystallites 2 are coupled in sequence, and a magneli phase 2a is formed on the surface of the crystallites 2. The crystallites 2 are oriented at random, coupled with each other via pinacoid or end surface, and laminated as the three-dimensional network structure. A large number of spaces 3 in nano size is present in the titanium oxide particles 1, a grain boundary of the bonding interface is eliminated between the crystallites 2, while a large number of pores is present.