Li0.84Ni0.08MnPO4/C　composite　cathode　materials　for　lithium　ion　battery　are　synthesized　by　sol-gel　method　followed　by　heat　treatment　in　the　air.　Field-emission　scanning　electron　microscopy　(FE-SEM)　measurements　show　that　firing　temperature　affects　the　morphology　of　the　end　products.　X-ray　powder　diffraction　(XRD)　analysis　indicates　that　the　samples　are　olivine-structured.　The　galvanostatic　charge-discharge　results　show　that　the　optimal　firing　temperature　registers　400　degrees　C,　and　that　sample　Ni008-20%-400　possessed　the　best　properties　with　its　initial　discharge　capacity　of　145.3　mAhg(-1)　at　0.02C　rate　and　good　capacity　retention　at　a　high　C-rate.