The present invention relates to a process for preparing an ammonium vanadium phosphate of formula (NH.sub.4)(VO.sub.2)(HPO.sub.4). It also relates to a process for preparing a vanadium orthophosphate VPO.sub.4.

The invention relates to a process for the preparation of sodium-based solid compounds, such as sodium-based solid alloys and sodium-based crystalline phases by ball-milling using metallic sodium as starting material. The invention also relates to some sodium-based crystalline P′2-phases and to Na-based vanadium phosphates phases (Na.sub.(3+y)V.sub.2(PO.sub.4).sub.3) with 0<y≤3 and Na-based vanadium fluorophosphates phases (Na.sub.(3+z)V.sub.2(PO.sub.4).sub.2F.sub.3) with 0<z≤3, in particular Na.sub.4V.sub.2(PO.sub.4).sub.2F.sub.3, obtained by such a process and to their use, as active material for positive electrode, in a Na-ion battery.

The invention relates to a process for the preparation of sodium-based solid compounds, such as sodium-based solid alloys and sodium-based crystalline phases by ball-milling using metallic sodium as starting material. The invention also relates to some sodium-based crystalline P′2-phases and to Na-based vanadium phosphates phases (Na.sub.(3+y)V.sub.2(PO.sub.4).sub.3) with 0<y≤3 and Na-based vanadium fluorophosphates phases (Na.sub.(3+z)V.sub.2(PO.sub.4).sub.2F.sub.3) with 0<z≤3, in particular Na.sub.4V.sub.2(PO.sub.4).sub.2F.sub.3, obtained by such a process and to their use, as active material for positive electrode, in a Na-ion battery.

A solid electrolyte including: a compound represented by Formula 1,

Li.sub.xM1.sub.2−yM2.sub.y(PO.sub.4−zX.sub.z).sub.3  Formula 1 wherein, in Formula 1, M1 is a tetravalent element, M2 is a monovalent element, a divalent element, a trivalent element, a tetravalent element, a pentavalent element, a hexavalent element, or a combination thereof, X is a halogen atom, a pseudohalogen, or a combination thereof, 0<x<8, 0≤y<1, and 0<z<4.

A flame-retardant compound, a process for forming a flame-retardant polymer, and an article of manufacture are disclosed. The flame-retardant compound includes at least one muconic acid moiety and at least one phosphorus-based moiety. The process for forming the flame-retardant polymer includes obtaining a muconic acid compound, obtaining a muconic acid compound, reacting the muconic acid compound with the phosphorus compound to form a flame-retardant compound, and incorporating the flame-retardant compound into a polymer. The article of manufacture comprises a material that contains a flame-retardant compound derived from muconic acid.

A flame-retardant compound, a process for forming a flame-retardant polymer, and an article of manufacture are disclosed. The flame-retardant compound includes at least one muconic acid moiety and at least one phosphorus-based moiety. The process for forming the flame-retardant polymer includes obtaining a muconic acid compound, obtaining a muconic acid compound, reacting the muconic acid compound with the phosphorus compound to form a flame-retardant compound, and incorporating the flame-retardant compound into a polymer. The article of manufacture comprises a material that contains a flame-retardant compound derived from muconic acid.

A positive electrode (21) includes a positive electrode current collector (21A), and a positive electrode mixture layer (21B) which is formed on the positive electrode current collector (21A) and contains a positive electrode active material. The positive electrode mixture layer (21B) includes a first positive electrode active material (21B-1) composed of LiVPO.sub.4F and a second positive electrode active material (21B-2) composed of LiVP.sub.2O.sub.7. In addition, a mixing ratio of the first positive electrode active material (21B-1) and the second positive electrode active material (21B-2) contained in the positive electrode mixture layer (21B) is represented by (1x)LiVPO.sub.4F+xLiVP.sub.2O.sub.7 (x is a mass ratio, 0<x0.21).

A method of producing an apatite crystal includes the steps of preparing an apatite single crystal expressed by the general formula M.sup.2.sub.5(PO.sub.4).sub.3X (M.sup.2 being at least atomic element selected from the group consisting of divalent alkaline-earth metals and Eu, and X is at least one atomic selected from the group consisting of halogens); placing the apatite single crystal into a space controllable to a predetermined atmosphere; supplying water vapor into the space; and heating such that the atmosphere in the space is within a 1000 C. to 1400 C. range.

A method of producing an apatite crystal includes the steps of preparing an apatite single crystal expressed by the general formula M.sup.2.sub.5(PO.sub.4).sub.3X (M.sup.2 being at least atomic element selected from the group consisting of divalent alkaline-earth metals and Eu, and X is at least one atomic selected from the group consisting of halogens); placing the apatite single crystal into a space controllable to a predetermined atmosphere; supplying water vapor into the space; and heating such that the atmosphere in the space is within a 1000 C. to 1400 C. range.

A solid conductor including: a compound represented by Formula 1, a compound represented by Formula 2, or a combination thereof

Li.sub.1+x+yzTa.sub.2-xM.sub.xP.sub.1-yQ.sub.yO.sub.8-zX.sub.z Formula 1

wherein, in Formula 1, M is an element having an oxidation number of +4, Q is an element having an oxidation number of +4, X is a halogen, a pseudohalogen, or a combination thereof, and 0x2, 0y<1, and 0z2, except that cases i) x and y and z are simultaneously 0, ii) M is Hf, X is F, x is 1 , y is 0, and z is 1, iii) M is Hf, X is Cl, x is 2, y is 0, and z is 2, and iv) M is Hf, X is F, x is 2, y is 0, and z is 2,

Li.sub.1+x+yzTa.sub.2-xM.sub.xP.sub.1-yQ.sub.yO.sub.8-zLiX Formula 2

wherein, in Formula 2, M is an element having an oxidation number of +4, Q is an element having an oxidation number of +4, X is a halogen, a pseudohalogen, or a combination thereof, and 0)(2, 0y<1, and 0z2, except that cases i) x and y and z are simultaneously 0, ii) M is Hf, X is F, x is 1 , y is 0, and z is 1, iii) M is Hf, X is Cl, x is 2, y is 0, and z is 2, and iv) M is Hf, X is F, x is 2, y is 0, and z is 2.