。1018 北京科技大学学报 第29卷 可逆性不高，从而证明了锐钛矿相TO2杂质的存在 达到170mAhg1,首次充放电库仑效率为92%： 对大电流密度下M2充放电性能的负面影响. 以175,350和875mA·g的电流密度放电的放电 容量分别达到了151,140和115mAhg,与L0H ----Ml 和Ti02(锐钛矿相固相烧结得到的Li4Ti5012(M2) -M2 相比较，性能分别提高了约5%，10%和26%. (2)循环伏安测试表明M1具有更高的氧化还 原反应可逆性及更高的电化学活性 参考文献 b.5 1.0152.02.53.03.5 电位N [I]Ohzuku T.UedaA,Yamamoto N.Why transition metal (di)ox- ides are the most attractive materials for batteries.Solid State 图6 LiTisOp的循环伏安曲线 1 onics1994.69:201 Fig.6 Cyclic voltammograms of LiTiO prepared by different [2 Ohzuku T.Ueda A.Yamamoto N.Zerr strain insertion material methods of Li LiTis3 0 for rechargeable lithium cells J Electrochem Sc,1995,142(5):1431 对M1电极，在充放电稳定后进行了交流阻抗 3 Colbow K M,Dahn J R.Hacring RR.Structure and electro 测试，电压幅值为10mV,频率范围为100kHz~ chemistry of the spinel oxides LiTiOand LisaTis30J Power 10mHz,如图7所示.经过拟合，充电后的电化学反 Sources.1989.26397 应电阻为202，放电后的电化学反应电阻为162. [4 Harrison M R.Edw ards PP.Goodenough J B.The supercon- 这是由于放电插锂后，富锂相中含有还原态的 ductorsemiconductor transition in the Li<Tix0 spinel sys T3+,使材料电导率增加，电化学反应阻抗降低. tem.Philos Mag B.1985.52(3):679 [5 Ferg E,Gummow R J,de Kock A.Spinel anodes for lithium-ion 7000-50a 一·一充电 batteries.J Electrochem Soc,1994.141(11):L147 4004 60 一放电 [6 Zaghib K.Simoneau M.Armand M.etal Electrochemical study 5000 -1.465He of LiTi2 as negative dlectmde for Li-ion polymer rechargeable 十100 4000 batteries.J Power Sources,1999,81/82:300 6204060和1002 33000 [7]Guerfi A.Charest P.Kinoshita K,et al.Nano dlectronically con- ductive titanium-spinel as ithium ion storage negative electrode. 2000 3 J.Power Sources 2004,126:163 1000 465 0 444 [8 Wang G X.Bradhurst D H,Dou S X.et al Spind Lil Li/3 -1000 Tisl O as an anode material for Ithium ion batteries.J Power 0 400 800 1200 1600 Sourc8,1999,83:156 ZIQ [9 Wen Z Y.Gu Z H.Huang S H.et al.Research on spray-dried 图7M1充电放电后交流阻抗图 lithium titanate as eectrode materials for lithium ion batteries.J Fig.7 Nyquist plots of ACimpedance spectra for MI charged and Power Sources 2005,146:670 discharged [10 Kavan L Fattakhova D.Krtil P.Lithium insertion into meso scopic and ingle-erystal Tia(rutile)eectrodes.J Electrochem S0c.1999.146(4):1375 3 结论 [11]Kavan L,Kratochvilo K.Gratzd M.Study of nanocrystalline TiO anatase)electrode in the accumulation regime.J Elec- (1)本文以LiNO3和Ti02(锐钛矿相)为反应 troanal Chem.1995.394 93 物固相合成了Li4Ti5012(M1),粒径主要在200~ 300nm之间.35mAg1电流密度下首次放电容量 (下转第1058页)可逆性不高, 从而证明了锐钛矿相 TiO2 杂质的存在 对大电流密度下 M 2 充放电性能的负面影响 . 图6 Li4Ti5O12的循环伏安曲线 Fig.6 Cyclic voltammograms of Li4Ti5O12 prepared by different methods 对 M1 电极, 在充放电稳定后进行了交流阻抗 测试, 电压幅值为 10 mV, 频率范围为 100 kHz ～ 10 mHz, 如图 7 所示.经过拟合, 充电后的电化学反 应电阻为 20 Ψ, 放电后的电化学反应电阻为 16 Ψ. 这是由于放电插锂后, 富锂相中含有还原态的 Ti 3 +, 使材料电导率增加, 电化学反应阻抗降低. 图7 M1 充电放电后交流阻抗图 Fig.7 Nyquist plots of AC impedance spectra for M1 charged and discharged 3 结论 ( 1) 本文以 LiNO3 和 TiO2( 锐钛矿相) 为反应 物固相合成了 Li4 Ti5O12 ( M 1) , 粒径主要在 200 ～ 300 nm 之间 .35 mA·g -1电流密度下首次放电容量 达到 170 mAh·g -1 , 首次充放电库仑效率为 92 %; 以 175, 350 和 875 mA·g -1的电流密度放电的放电 容量分别达到了 151, 140 和 115 mAh·g -1 , 与 LiOH 和 TiO2( 锐钛矿相) 固相烧结得到的 Li4 Ti5O12( M 2) 相比较, 性能分别提高了约 5 %, 10 %和 26 %. ( 2) 循环伏安测试表明 M 1 具有更高的氧化还 原反应可逆性及更高的电化学活性. 参 考 文 献 [ 1] Ohzuku T, Ueda A, Yamamoto N .Why transition met al ( di) ox￾ides are the most attractive mat erials f or batteries.Solid State Ionics, 1994, 69:201 [ 2] Ohzuku T, Ueda A, Yamamoto N.Zero-strain insertion material of Li[ Li 1/3Ti 5/3 ] O4 for rechargeable lithium cells.J Electrochem Soc, 1995, 142( 5) :1431 [ 3] Colbow K M, Dahn J R, Haering R R.Structure and electro￾chemistry of the spinel oxides LiTi2O4 and Li4/3Ti5/3O4.J Power Sources, 1989, 26:397 [ 4] Harrison M R, Edw ards P P, Goodenough J B .The supercon￾ductor-semi conduct or transition in the Li 1+x Ti 2-x O4 spinel sys￾tem .Philos Mag B, 1985, 52( 3) :679 [ 5] Ferg E, Gummow R J, de Kock A.S pinel anodes for lithium-ion batteries.J Electrochem Soc, 1994, 141(11) :L147 [ 6] Zaghib K, Simoneau M, Armand M, et al.Electrochemical study of Li 4Ti 5O12 as negative electrode for Li-ion polymer rechargeable batteries.J Power Sources, 1999, 81/ 82:300 [ 7] Guerfi A, Charest P, Kinoshita K, et al.Nano electronically con￾ductive tit anium-spinel as lithium ion st orage negative electrode . J.Power Sources, 2004, 126:163 [ 8] Wang G X, Bradhurst D H, Dou S X, et al.Spinel Li[ Li 1/3 Ti5/3] O4 as an anode mat erial f or lithium ion batteries.J Power Sources, 1999, 83:156 [ 9] Wen Z Y, Gu Z H, Huang S H, et al.Research on spray-dried lithium tit anate as electrode materials for lithium ion batteries.J Power Sources, 2005, 146:670 [ 10] Kavan L, Fattakhova D, Krtil P .Lithium insertion in to meso￾scopic and single-cryst al TiO2( rutile) electrodes.J Electrochem Soc, 1999, 146( 4) :1375 [ 11] Kavan L, Kratochvilová K, Grätzel M .Study of nanocrystalline TiO2 ( anatase ) electrode in the accumulation regime.J Elec￾troanal Chem, 1995, 394:93 ( 下转第 1058 页) · 1018 · 北 京 科 技 大 学 学 报 第 29 卷