物理化学学报
物理化學學報
물이화학학보
ACTA PHYSICO-CHIMICA SINICA
2013年
4期
763-769
,共7页
尖晶石LiMn2O4%锗掺杂%锡掺杂%固相反应%循环性能
尖晶石LiMn2O4%鍺摻雜%錫摻雜%固相反應%循環性能
첨정석LiMn2O4%타참잡%석참잡%고상반응%순배성능
Spinel LiMn2O4%Ge4+doping%Sn4+doping%Solid-state reaction%Cycleability
使用Ge4+、Sn4+作为掺杂离子,通过高温固相法制备四价阳离子掺杂改性的尖晶石LiMn2O4材料. X射线衍射(XRD)和扫描电子显微镜(SEM)分析表明, Ge4+离子取代尖晶石中Mn4+离子形成了LiMn2-xGexO4(x=0.02,0.04,0.06)固溶体;而Sn4+离子则以SnO2的形式存在于尖晶石LiMn2O4的颗粒表面. Ge4+离子掺入到尖晶石LiMn2O4材料中,抑制了锂离子在尖晶石中的有序化排列,提高了尖晶石LiMn2O4的结构稳定性;而在尖晶石颗粒表面的SnO2可以减少电解液中酸的含量,抑制酸对LiMn2O4活性材料的侵蚀.恒电流充放电测试表明,两种离子改性后材料的容量保持率均有较大幅度的提升,有利于促进尖晶石型LiMn2O4锂离子电池正极材料的商业化生产.
使用Ge4+、Sn4+作為摻雜離子,通過高溫固相法製備四價暘離子摻雜改性的尖晶石LiMn2O4材料. X射線衍射(XRD)和掃描電子顯微鏡(SEM)分析錶明, Ge4+離子取代尖晶石中Mn4+離子形成瞭LiMn2-xGexO4(x=0.02,0.04,0.06)固溶體;而Sn4+離子則以SnO2的形式存在于尖晶石LiMn2O4的顆粒錶麵. Ge4+離子摻入到尖晶石LiMn2O4材料中,抑製瞭鋰離子在尖晶石中的有序化排列,提高瞭尖晶石LiMn2O4的結構穩定性;而在尖晶石顆粒錶麵的SnO2可以減少電解液中痠的含量,抑製痠對LiMn2O4活性材料的侵蝕.恆電流充放電測試錶明,兩種離子改性後材料的容量保持率均有較大幅度的提升,有利于促進尖晶石型LiMn2O4鋰離子電池正極材料的商業化生產.
사용Ge4+、Sn4+작위참잡리자,통과고온고상법제비사개양리자참잡개성적첨정석LiMn2O4재료. X사선연사(XRD)화소묘전자현미경(SEM)분석표명, Ge4+리자취대첨정석중Mn4+리자형성료LiMn2-xGexO4(x=0.02,0.04,0.06)고용체;이Sn4+리자칙이SnO2적형식존재우첨정석LiMn2O4적과립표면. Ge4+리자참입도첨정석LiMn2O4재료중,억제료리리자재첨정석중적유서화배렬,제고료첨정석LiMn2O4적결구은정성;이재첨정석과립표면적SnO2가이감소전해액중산적함량,억제산대LiMn2O4활성재료적침식.항전류충방전측시표명,량충리자개성후재료적용량보지솔균유교대폭도적제승,유리우촉진첨정석형LiMn2O4리리자전지정겁재료적상업화생산.
@@@@Spinel LiMn2O4 materials doped with tetravalent cations Ge4+and Sn4+were synthesized through solid-state reaction. Analysis of the materials by X-ray diffraction (XRD) and scanning electron microscopy (SEM) suggested that Ge4+ions occupied octahedral sites by substituting Mn4+ions in the spinel structure to form the solid solution LiMn2-xGexO4 (x=0.02, 0.04, 0.06), while Sn4+ions were present at the surface of the spinel LiMn2O4 as SnO2. The substitution of Mn4+with Ge4+could suppress the long-range ordering of the Li+ions in the spinel LiMn2O4, enhancing its stability. SnO2 on the surface of LiMn2O4 could reduce the acidity of the liquid electrolyte, suppressing acid etching of the LiMn2O4 active material. Galvanostatic charge/discharge tests showed that both Ge4+ and Sn4+-modified spinel LiMn2O4 materials exhibited significantly higher capacity retention than LiMn2O4. The increased capacity retention should benefit the application of spinel LiMn2O4 as a cathode material for lithium-ion batteries.
