Synthesis, Structure, and Magnetic Properties of [Li(H2O)M(N2H3CO2)3]·0.5H2O (M = Co,Ni) as Single Precursors to LiMO2
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- 作者：Szu Lui Tey ; M. V. Reddy ; G. V. Subba Rao ; B. V. R. Chowdari ; Jiabao Yi ; Jun Ding ; and Jagadese J. Vittal
- 刊名：Chemistry of Materials
- 出版年：2006
- 出版时间：March 21, 2006
- 年：2006
- 卷：18
- 期：6
- 页码：1587 - 1594
- 全文大小：211K
- 年卷期：v.18,no.6(March 21, 2006)
- ISSN：1520-5002
文摘
[Li(H2O)M(N2H3CO2)3]·0.5H2O, M = Ni (1) and Co (2), has been synthesized in moderate yield fromthe corresponding metal salts and hydrazinecarboxylate anion, N2H3CO2-, prepared by mixing N2H4·H2O and dry ice. Both the compounds crystallized in the chiral space group P21 and have interesting 2Dbilayer network structures in the solid state comprising fused helical coordination polymers with extensivehydrogen bonding. Samples 1 and 2 exhibited paramagnetism, as shown by the variable temperaturemagnetic measurements. The calculated magnetic moments were 2.82 and 4.39 
B for 1 and 2, respectively.These two compounds have been investigated as single precursors for layered materials LiMO2, M = Niand Co. Pyrolysis of 1 and 2 yields LiNiO2 and LiCoO2 at 700 
C in an oxygen atmosphere and at T >700 C in air, respectively. They were characterized by powder XRD, Rietveld refinement, and SEM.Cathodic properties of LiMO2 have been evaluated by cyclic voltammetry and galvanostatic charge-discharge cycling up to 20 cycles in the voltage ranges, 2.5-4.3 and 2.5-4.5 V vs Li metal. Results arein tune with those reported in the literature, thereby indicating that 1 and 2 are excellent single-sourceprecursors for obtaining electrochemically active battery materials.
B for 1 and 2, respectively.These two compounds have been investigated as single precursors for layered materials LiMO2, M = Niand Co. Pyrolysis of 1 and 2 yields LiNiO2 and LiCoO2 at 700 C in an oxygen atmosphere and at T >700 C in air, respectively. They were characterized by powder XRD, Rietveld refinement, and SEM.Cathodic properties of LiMO2 have been evaluated by cyclic voltammetry and galvanostatic charge-discharge cycling up to 20 cycles in the voltage ranges, 2.5-4.3 and 2.5-4.5 V vs Li metal. Results arein tune with those reported in the literature, thereby indicating that 1 and 2 are excellent single-sourceprecursors for obtaining electrochemically active battery materials.