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 (1−x)LiVPO.sub.4F+xLiVP.sub.2O.sub.7 (x is a mass ratio, 0<x≤0.21).

A lithium oxide coated with carbon, wherein the carbon contains co-continuous fibrous carbon having a three-dimensional network structure in which carbon is branched.

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 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.

A preparation method of CsDFP for aqueous negative electrode slurry includes carrying out ion exchange reactions with LiPO.sub.2F.sub.2 and a cesium source. The activation energy of Li.sup.+ intercalation in the negative electrode is reduced due to the existence of Cs.sup.+, leading to a better rate performance. Further, the impedance growth rate of the batteries is reduced and the high temperature storage performance is excellent since PO.sub.2F.sub.2— participates in the electrochemical reaction to form a stable low-impedance SEI film on the surface of the negative electrode plate. Moreover, films are continuously formed to repair the SEI films under the gradual release of CsDFP, which is conducive to inhibiting the growth of lithium dendrites during long-term high-rate cycling, thereby obtaining an improved cycle performance.

The invention relates to a glass including, as represented by mol % based on elements: 8-25% of P; 8-40% of Sn; 20-80% of O; and 1-50% of F, in which the glass has a glass transition temperature Tg of 300° C. or lower, and the glass gives an infrared absorption spectrum satisfying A3240/A3100 of 0.6-1.2, where the A3100 is an absorbance per 1-mm thickness at a wavenumber of 3,100 cm.sup.−1 and the A3240 is an absorbance per 1-mm thickness at a wavenumber of 3,240 cm.sup.−1.

The invention relates to a glass including, as represented by mol % based on elements: 8-25% of P; 8-40% of Sn; 20-80% of O; and 1-50% of F, in which the glass has a glass transition temperature Tg of 300° C. or lower, and the glass gives an infrared absorption spectrum satisfying A3240/A3100 of 0.6-1.2, where the A3100 is an absorbance per 1-mm thickness at a wavenumber of 3,100 cm.sup.−1 and the A3240 is an absorbance per 1-mm thickness at a wavenumber of 3,240 cm.sup.−1.

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.

Provided are an electrolyte solution for a lithium secondary battery, and a lithium secondary battery including the electrolyte solution. The electrolyte solution for a lithium secondary battery includes a lithium salt, an organic solvent, and further quaternary ammonium hexafluorophosphate as a solid salt.