Lithium phosphate olivine

Reversible electrochemical lithium deintercalation from 2D and 3D materials is important for applications in lithium-ion batteries. New developments have been realized in two classes of materials that show exceptionally promising properties as cathode materials. The first includes mixed layered oxides exemplified by LijMn Nij, Co ]02, where the Mn remains inert to oxidation/reduction and acts as a framework stabilizer while the other elements carry the redox load. Another class that shows much potential is metal phosphates, which includes olivine-type LiFeP04, and the NASICON-related frameworks Li3M2(P04)3. 

Since the pioneering work of Padhi et al., numerous studies dedicated to improving the electrochemical characteristics of the phospho-olivines have been undertaken. Among the different phospho-olivine materials studied for use in lithium-ion rechargeable cells, the most promising phosphate is LiFeP04, and recently Chung et al. have shown that it is possible to enhance the electronic... 

Phospho-olivines as lithium intercalation materials were reported early in 1997. Unfortunately, researchers did not pay much attention to them because olivine phosphates with low electronic conductivity did not allow most of the lithium ions to intercalate/de-intercalate reversibly. This low reversibility could lead to low capacity, particularly at high current densities. Under the strong driving force of safety requirements when lithium ion batteries are used commercially for both portable devices and EV/HEV applications, olivine phosphate cathode materials, especially LiFeP04, have been revisited globally by researchers since the beginning of the 2F century. Attractive features are... 

Lithium cobalt phosphate, LiCoP04 (LCP) has attracted attention since it offers both flat high potential (at approximately 4.8 V vs. Li /Li" ), good theoretical capacity (167 mAg ) and smaller structure volume change. As other olivine compounds, LCP crystallizes with the orthorhombic symmetry (Pnma S.G.) with lattice parameters a = 10.2048 A,b = 5.9245 A, and c = 4.7030 A. However, like in the case of LiMnP04, the electrochemical performance of pristine LCP is very poor due to the low intrinsic electronic and ionic conductivity [67, 102-116]. Zhao et al. [116] prepared LCP micro-rods with the diameter of ca. 500 nm and length of ca. 5 pm by a hydrothermal method, which delivered a discharge capacity of only... 

Koleva V, Zhecheva E, Stoyanova R (2010) Oidtaed olivine-type lithium-cobalt and lithium-nickel phosphates prepared by a new precursor method. Eur J friorg Chem 26 4091—4099... 

Lithium ferrous(II) phosphate (LiFeP04) is a positive electrode material for lithium-ion batteries, which, so far, has been mainly used in power lithium-ion batteries [1]. It is commonly called lithium iron(II) phosphate and is also used in fertilizers. In 1996, the Japanese NTT Corporation disclosed for the first time an olivine structured compound, A MP04 (A is an alkali metal and M a combination of Co and Fe) as a positive electrode material for lithium-ion batteries. In 1997, Prof. John B. Goodenough and his group at the University of Texas at Austin, United States, reported the characteristics of reversible lithium intercalation/deintercalation into/from LiFeP04. However, at the initial stage, this positive electrode material did not raise much attention since its electronic and ionic conductivities are very low and... 

Meethong, N., Kao, Y.-H., Speakman, S. A Chiang, Y.-M. Aliovalent substitutions in olivine lithium iron phosphate and impact on structure and properties. Adv. Funct. Mater., 19,1060-1070 (2009). 

Dai D, Koo HJ, Rocquefelte X, Jobic S (2005) Analysis of the spin exchange interactions and the ordered magnetic structures of lithium transition metal phosphates LiMPOa (M = Mn, Fe, Co, Ni) with the olivine structure. Inorg Chem 44 2407-2413... 

In the search of new cathodes, parhcular attention is addressed to materials of the olivine family and, in particular, on lithium iron phosphate, LiFeP04 [29]. This interest is motivated by the many appealing features of this com-poxmd, which include good capacity (170 mAh g i), a two-phase electrochemical process that evolves with a flat 3.5 V vs. Li voltage (see Figure 3.23),... 

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