The recycling of LiCoO2 cathode materials from spent li thium ion batteries was studied.A corresponding process was proposed.Propylene c arbonate was used as the solvent to recycle electrolyte.NMP was used as the solv...The recycling of LiCoO2 cathode materials from spent li thium ion batteries was studied.A corresponding process was proposed.Propylene c arbonate was used as the solvent to recycle electrolyte.NMP was used as the solv ent to separate the active materials from current collectors at 70 ℃.Carbon pow der was removed by heat-treatment. Cobalt compounds were dissolved by HCl solu tion and recycled as Co（OH）2. The recycled Co（OH）2 was used as t he starting material to synthesize LiCoO2.The net recovery of cobalt was more than 99%.The analytical results of recycled LiCoO2 showed that the recycling p rocess was practical.展开更多
The LiMn2O4 spinel was prepared by wet method using Li2CO3, Mn(CH3COO)2·4H2O and CO2 as raw materials. The products were measured by TG/DTA, XRD, IR. The results Showed that the sample calcined at 800℃for 10h wa...The LiMn2O4 spinel was prepared by wet method using Li2CO3, Mn(CH3COO)2·4H2O and CO2 as raw materials. The products were measured by TG/DTA, XRD, IR. The results Showed that the sample calcined at 800℃for 10h was well crystallized monophase product. The contents of Mn?and Mn?of LiMn2O4 spinel were determined simultaneously by spectrophotometric analysis with pyrophosphoric acid.展开更多
The paper first reported the preparation of ultrafine Fe3O4 powder about 8～ 10nm by improved chemical precipitation method, then turned it into magnetic fluid. The phase analysis, morphology, ultrafine powder size an...The paper first reported the preparation of ultrafine Fe3O4 powder about 8～ 10nm by improved chemical precipitation method, then turned it into magnetic fluid. The phase analysis, morphology, ultrafine powder size and magnetic property were measured by XRD, TEM and vibrating sample magnetometer(VSM),respectively. In addition, a new method , by analyzed the suspending percentage of Fe3O4 powder, was introduced to study the effects of concentration, pH value, centrifugal rate and time on the stability of the magnetic fluid.展开更多
In this paper, we report a new kind of moist chemical method for preparing LiNiVO 4 which can be used to prepare lithium ion battery for the cathode active materials with a very high battery voltage(48 V vs. Li). Li 2...In this paper, we report a new kind of moist chemical method for preparing LiNiVO 4 which can be used to prepare lithium ion battery for the cathode active materials with a very high battery voltage(48 V vs. Li). Li 2CO 3, NiCO 3 and NH 4VO 3 were used as row materials, and H 2C 2O 4 saturated solution was used both as a precipitate agent and as a complex agent. The precursor gel composed of (NH 4) 2(VO) 2(C 2O 4) 4·6H 2O, NiC 2O 4·2H 2O and Li 2C 2O 4 can be obtained, and after sintering the dry gel we got the products. The results of XRD show that the product sintered at 400 ℃ for 2 h exists in a cubic crystal, single phase, inverse LiNiVO 4 and the average sizes (by Scherrer formula ) were 40—50 nm(400 ℃, 2 h ) and 65—70 nm(700 ℃, 2 h) , respectively, a=0.822 3(1) nm. The TG and DTA curves implied that the dry gel underwent water loss, decompositions of oxalates and complex oxalate, the solid state reactions finished at 377 ℃. The results of XPS proved that the valence in LiNiVO 4 would be Li+,V 5+ , Ni 2+ (in the main), respectively. From ICP analysis we also knew that the sample corresponded basically to stoichiometry LiNiVO 4 .展开更多
The vanadates of LiNi1-xMxVO4(M=Fe,Co,Ni) containing VO4 tetrahedrons were synthesized by soft chemical method through a new mild liquid route. The samples sintered at 450℃ for 3h and at 650℃ for 3h are named for LT...The vanadates of LiNi1-xMxVO4(M=Fe,Co,Ni) containing VO4 tetrahedrons were synthesized by soft chemical method through a new mild liquid route. The samples sintered at 450℃ for 3h and at 650℃ for 3h are named for LT LiNiVO4 and for MT LiNi1-xMxVO4 respectively. All of the products were measured by X ray diffraction, IR and Raman spectra respectively. In comparison with IR spectra of V2O5 and NiO, the LT LiNiVO4 has a strong and broad IR absorption band of VO4 tetrahedrons located at 600～850cm-1 with three small splitting peaks corresponding to the asymmetry stretching vibrations of V O bonds. The results of IR and Raman spectra for MT LiNi1-xMxVO4 show that the cations of Ni2+, Co2+, Fe2+ have the influences on the frequency shifts of the V O vibrations.展开更多
文摘The recycling of LiCoO2 cathode materials from spent li thium ion batteries was studied.A corresponding process was proposed.Propylene c arbonate was used as the solvent to recycle electrolyte.NMP was used as the solv ent to separate the active materials from current collectors at 70 ℃.Carbon pow der was removed by heat-treatment. Cobalt compounds were dissolved by HCl solu tion and recycled as Co（OH）2. The recycled Co（OH）2 was used as t he starting material to synthesize LiCoO2.The net recovery of cobalt was more than 99%.The analytical results of recycled LiCoO2 showed that the recycling p rocess was practical.
文摘The LiMn2O4 spinel was prepared by wet method using Li2CO3, Mn(CH3COO)2·4H2O and CO2 as raw materials. The products were measured by TG/DTA, XRD, IR. The results Showed that the sample calcined at 800℃for 10h was well crystallized monophase product. The contents of Mn?and Mn?of LiMn2O4 spinel were determined simultaneously by spectrophotometric analysis with pyrophosphoric acid.
文摘The paper first reported the preparation of ultrafine Fe3O4 powder about 8～ 10nm by improved chemical precipitation method, then turned it into magnetic fluid. The phase analysis, morphology, ultrafine powder size and magnetic property were measured by XRD, TEM and vibrating sample magnetometer(VSM),respectively. In addition, a new method , by analyzed the suspending percentage of Fe3O4 powder, was introduced to study the effects of concentration, pH value, centrifugal rate and time on the stability of the magnetic fluid.
文摘In this paper, we report a new kind of moist chemical method for preparing LiNiVO 4 which can be used to prepare lithium ion battery for the cathode active materials with a very high battery voltage(48 V vs. Li). Li 2CO 3, NiCO 3 and NH 4VO 3 were used as row materials, and H 2C 2O 4 saturated solution was used both as a precipitate agent and as a complex agent. The precursor gel composed of (NH 4) 2(VO) 2(C 2O 4) 4·6H 2O, NiC 2O 4·2H 2O and Li 2C 2O 4 can be obtained, and after sintering the dry gel we got the products. The results of XRD show that the product sintered at 400 ℃ for 2 h exists in a cubic crystal, single phase, inverse LiNiVO 4 and the average sizes (by Scherrer formula ) were 40—50 nm(400 ℃, 2 h ) and 65—70 nm(700 ℃, 2 h) , respectively, a=0.822 3(1) nm. The TG and DTA curves implied that the dry gel underwent water loss, decompositions of oxalates and complex oxalate, the solid state reactions finished at 377 ℃. The results of XPS proved that the valence in LiNiVO 4 would be Li+,V 5+ , Ni 2+ (in the main), respectively. From ICP analysis we also knew that the sample corresponded basically to stoichiometry LiNiVO 4 .
文摘The vanadates of LiNi1-xMxVO4(M=Fe,Co,Ni) containing VO4 tetrahedrons were synthesized by soft chemical method through a new mild liquid route. The samples sintered at 450℃ for 3h and at 650℃ for 3h are named for LT LiNiVO4 and for MT LiNi1-xMxVO4 respectively. All of the products were measured by X ray diffraction, IR and Raman spectra respectively. In comparison with IR spectra of V2O5 and NiO, the LT LiNiVO4 has a strong and broad IR absorption band of VO4 tetrahedrons located at 600～850cm-1 with three small splitting peaks corresponding to the asymmetry stretching vibrations of V O bonds. The results of IR and Raman spectra for MT LiNi1-xMxVO4 show that the cations of Ni2+, Co2+, Fe2+ have the influences on the frequency shifts of the V O vibrations.
