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1、第26卷第1期無機(jī)化學(xué)學(xué)報(bào)V0l
2、26No.12010年1月CHINESEJOURNALOFIN0RGANICCHEMISTRY126—13l磷酸釩鋰正極材料的合成與性能研究李麗·李國華2王石泉1馮傳啟,(湖北大學(xué)化學(xué)化工學(xué)院,武漢430062)(浙江工業(yè)大學(xué)綠色化學(xué)合成技術(shù)國家重點(diǎn)實(shí)驗(yàn)室.杭州3100321摘要:本文以LiOH·H20,NHVO3,NH4H2PO4和檸檬酸等為原料采用流變相法成功地合成了磷酸釩鋰化合物。利用XRD,TEM等手段對(duì)目標(biāo)產(chǎn)物的結(jié)構(gòu)和形貌進(jìn)行了表征,結(jié)果表明:在800℃煅燒的樣品具有單一純相的單斜晶體結(jié)構(gòu)。晶體顆粒分布在200-500nm范圍
3、,而且在顆粒表面包覆了一層碳,有利于材料的導(dǎo)電率的改善。對(duì)該材料的電化學(xué)性質(zhì)進(jìn)行了測試,實(shí)驗(yàn)發(fā)現(xiàn):800℃煅燒的樣品在0.1C和1C倍率電流條件下,首次放電比容量分別高達(dá)122.8和107mAh·,經(jīng)過30次循環(huán)后容量衰減很少。交流阻抗譜證實(shí)了800℃煅燒的樣品具有較高的電導(dǎo)率。本文對(duì)800℃煅燒的樣品具有較好電化學(xué)性能的原因進(jìn)行了初步討論。關(guān)鍵詞:磷酸釩鋰;正極材料;流變相反應(yīng)法:電化學(xué)性能中圖分類號(hào):0614.111;0614.511;TM912.9文獻(xiàn)標(biāo)識(shí)碼:A文章編號(hào):1001—4861(2010)01—0126—06SynthesisandElectroche
4、micalCharacteristicsofCathodeMaterialsLi3v2(P04)3LIIJiLIGuo-HuaWANGShi—QuanFENGChuan—Qi,(。CollegeofChemistryandChemicalEngineering,HubeiUniversity,Wuh~t430062)£KeyLaboratoryofGreenChemistrySynthesisTechnique,ZhejiangUniversityofTechnology,Hangzhou3100321Abstract:Anovelrheologicalphasemet
5、hodwasusedtosynthesizenanocrystallineLi3V2(P04)3compound.Inthisroute,LiOH·H2O,NH4VO3,NH4H2P04andcitricacidwereselectedasstartingmaterialstoprepareprecursor,andtheLi3V2(PO4)3wasobtainedbysinteringprecursoratdiferenttemperaturefor8hinflowingargon.TheLi3V2(P04)3hasbeencharacterizedbyXRDandT
6、EMtechniques,thecompoundsynthesizedat800℃takeonpuremonocliniccrystalstructure.theparticlesizeofthesamplesarerangedfrom200~500nmandthereisalayerofcarbonparticlesonthesurfaceofLi3V2(P04)3particles,whichisavailableforenhancingtheconductivityofLi3Vz(P04)3.Theinfluenceofsinteringtemperatureso
7、nelectrochemicalpropertiesofLi3V2(P04)3hasbeeninvestigatedalso,theresultsshowedthattheLi3V2(P04)3synthesizedat800oCexhibitedthehighestinitialdischargecapacity(122mAh·g-at0.1Cand107mAh·g~at1C,respectively)andgoodcapacityretentioninthevoltagerangeof3.0~4.3V.Theelectrochemicalimpedancespect
8、roscopy(EIS)showedthatthesamplesynthesizedat800℃behavedthehigherconductivity.ThereasonsfortheexcellentelectrochemicalperformanceofthecarboncoatedLi3V2(P04)3calcinedat800oCcathodematerialwerepresentedalso.Keywords:lithiumvanadiumphosphate;cathodematerials;rheologicalphaser