TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Method: The preparation of lithium sulfur battery involves providing lithium-rich compound (10-40 mass%) as third electrode. Preferred Properties: The lithium-rich compound is provided with irreversible lithium de-intercalation performance.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The elemental sulfur is sublimed sulfur or high-purity sulfur including sulfur/carbon compound, where carbon material is carbon nanotube, carbon nanofiber, active carbon, carbon aerogel, and carbon black; sulfur/conductive polymer compound, being polyaniline, polypyrrole and polythiophene; and sulfur/inorganic oxide compound, where inorganic oxide is yttrium oxide, lanthanum oxide, cerium oxide, or titanium oxide. The sulfur-based compound is dilithium sulfide of formula Li2Sn, where n is greater than or equal to 1, organic sulfur compound, and carbon sulfur polymer of formula (C2Sx)n, where x is 2.5-10, n greater than or equal to 2.    TECHNOLOGY FOCUS - METALLURGY - Preferred Components: The lithium-rich compound is lithium metal oxide of formula (LiMO2), lithium manganese metal oxide of formula (LiMn2-xMxO4), lithium nickel metal oxide of formula (LiNixM1-xO2), lithium nickel manganese cobalt oxide of formula (LiNixMnyCozO2), lithium iron phosphate, dilithium iron phosphate, lithium metal nitrides of formula (Li3-xMxN), lithium manganese nitride of formula (Li7-xMnxN4), lithium iron nitride of formula (Li3-xFexN2), dilithium sulfide or dilithium disulfide.M=Co, Ni, Mn, Cu, Cr or Fe (for LiMO2);orM=Ni, Co, or Cu (for LiMn2-xMxO4), where x is 0-1; orM=Cr, Fe or V (for LiMn2-xMxO4, where x is 0-0.5);orM=Co, Mn, Cu, Cr, Fe, V, La, Al, Mg, Ga, or Zn (for LiNixM1-xO2, where x is 0-1); orx+y+z=1 (for LiNixMnyCozO2);orM=Co, Ni, Cu, Cr or V( for Li3-xMxN, where x is 0-1); orx=0-1 (for Li7-xMnxN4 or Li3-xFexN2).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The carbon material is graphite, refinery coke, mesophase carbon microbead, mesophase carbon fiber, high-polymer pyrolytic carbon and carbon nanotube.