A positive electrode active material for nonaqueous electrolyte secondary batteries according to the present invention is a composite oxide which is represented by general formula Li.sub.xTM.sub.tmM.sub.yO.sub.2-fF.sub.f and has a crystal structure that belongs to the space group Fm-3m; and in the general formula, TM represents a transition metal, M represents a non-transition metal, and if Q=2tm(1(1f/2).sup.5), Q<1 is satisfied. With respect to a dV/dq-SOC curve showing the relationship between the state of charge SOC and dV/dq of a half cell that contains this composite oxide, the dV/dq-SOC curve being obtained by charging the half cell with a charging current of 0.1 C at 25 C. to an end voltage within the range of 4.7 V to 4.95 V, there is one or more peaks within the SOC range from 10% to 40%.

A positive electrode active material for nonaqueous electrolyte secondary batteries according to the present invention is a composite oxide which is represented by general formula Li.sub.xTM.sub.tmM.sub.yO.sub.2-fF.sub.f and has a crystal structure that belongs to the space group Fm-3m; and in the general formula, TM represents a transition metal, M represents a non-transition metal, and if Q=2tm(1(1f/2).sup.5), Q<1 is satisfied. With respect to a dV/dq-SOC curve showing the relationship between the state of charge SOC and dV/dq of a half cell that contains this composite oxide, the dV/dq-SOC curve being obtained by charging the half cell with a charging current of 0.1 C at 25 C. to an end voltage within the range of 4.7 V to 4.95 V, there is one or more peaks within the SOC range from 10% to 40%.

A disordered rocksalt (DRS) having improved characteristic has a cation comprised of lithium and one other metal and an anion comprised of oxygen and fluorine, and one or more of phosphorous, sulfur, and nitrogen. The substitution of one or more of P, S, and N on the oxygen anion site may realize improved cycle life of the battery and/or may be useful to make safer batteries.

A disordered rocksalt (DRS) having improved characteristic has a cation comprised of lithium and one other metal and an anion comprised of oxygen and fluorine, and one or more of phosphorous, sulfur, and nitrogen. The substitution of one or more of P, S, and N on the oxygen anion site may realize improved cycle life of the battery and/or may be useful to make safer batteries.

Lithium-containing thiostannate spinel compounds having the formula Li.sub.2M.sub.1+xSn.sub.3xS.sub.8, where x is 0 or 1 and M is Mg, Fe, Mn, Ni, Ga, In, or a combination thereof; or the formula Li.sub.1.66CuSn.sub.3.33S.sub.8 are provided. Methods and devices for detecting incident neutrons and alpha-particles using the compounds are also provided. For thermal neutron detection applications, the compounds can be enriched with lithium-6 isotope (.sup.6Li) to enhance their neutron detecting capabilities.

Lithium-containing thiostannate spinel compounds having the formula Li.sub.2M.sub.1+xSn.sub.3xS.sub.8, where x is 0 or 1 and M is Mg, Fe, Mn, Ni, Ga, In, or a combination thereof; or the formula Li.sub.1.66CuSn.sub.3.33S.sub.8 are provided. Methods and devices for detecting incident neutrons and alpha-particles using the compounds are also provided. For thermal neutron detection applications, the compounds can be enriched with lithium-6 isotope (.sup.6Li) to enhance their neutron detecting capabilities.

Improved methods for preparing lithium transition metal oxide particulate such as lithium nickel metal cobalt oxide (NMC) for use in lithium batteries and other applications are disclosed. The lithium transition metal oxide particulate is prepared from appropriate transition metal oxide and Li compound precursors mainly using dry, solid state processes including dry impact milling and heating. Further, novel precursor particulates and novel methods for preparing precursor particles for this and other applications are disclosed.

Improved methods for preparing lithium transition metal oxide particulate such as lithium nickel metal cobalt oxide (NMC) for use in lithium batteries and other applications are disclosed. The lithium transition metal oxide particulate is prepared from appropriate transition metal oxide and Li compound precursors mainly using dry, solid state processes including dry impact milling and heating. Further, novel precursor particulates and novel methods for preparing precursor particles for this and other applications are disclosed.

A positive electrode active material for nonaqueous electrolyte secondary batteries according to the present invention is characterized by being a composite oxide which is represented by general formula LixTMtmNMyO2-fFf and has a crystal structure that belongs to the space group Fm-3m. In the general formula, TM represents a transition metal; M represents a non-transition metal; x, tm, y and f satisfy 1.75x+tm+y2 and 0<f0.7; and if Q=2tm(1(1f/2)5), 0.8Q1.5 is satisfied.

A positive electrode active material for nonaqueous electrolyte secondary batteries according to the present invention is characterized by being a composite oxide which is represented by general formula LixTMtmNMyO2-fFf and has a crystal structure that belongs to the space group Fm-3m. In the general formula, TM represents a transition metal; M represents a non-transition metal; x, tm, y and f satisfy 1.75x+tm+y2 and 0<f0.7; and if Q=2tm(1(1f/2)5), 0.8Q1.5 is satisfied.