Crystal Chemistry of the Olivine-Type Li ( Mn y Fe1 − y ) PO 4 and ( Mn y Fe1 − y ) PO 4 as Possible 4 V Cathode Materials for Lithium Batteries

A potential 4 V cathode material for lithium batteries was investigated. The crystal chemistry of the olivine-type of Li(Mn y 2+ Fe 1-y 2+ )PO 4 (discharged state) and its delithiated form (Mn y 3+ Fe 1-y 3+ )PO 4 (charged state) were comparatively studied using X-ray diffraction, Mossbauer spectroscopy, and ab initio calculations. A strong oxidizer, nitronium tetrafluoroborate, NO 2 BF 4 , was used for chemical delithiation of Li(Mn y 2+ Fe 1-y 2+ )PO 4 to obtain (Mn y 3+ Fe 1-y 3+ )PO 4 . The strong electron/lattice interaction induced by the trivalent manganese (3d 4 ) in (Mn y 3+ Fe 1-y 3+ )PO 4 (charged state) is highlighted as the intrinsic obstacle to generating the full theoretical capacity (ca. 170 mAh/g) of the Mn-rich phase (y >0.8), followed by an efficient cathode performance of the optimized Li(Mn 0.6 Fe 0.4 )PO 4 .

[1]  K. Amine,et al.  OLIVINE LICOPO4 AS 4.8 V ELECTRODE MATERIAL FOR LITHIUM BATTERIES , 1999 .

[2]  John B. Goodenough,et al.  Lithium insertion into manganese spinels , 1983 .

[3]  Francis J. DiSalvo,et al.  Powerful oxidizing agents for the oxidative deintercalation of lithium from transition-metal oxides , 1989 .

[4]  Dominique Guyomard,et al.  Self-discharge of LiMn2O4/C Li-ion cells in their discharged state: Understanding by means of three-electrode measurements , 1998 .

[5]  John O. Thomas,et al.  Thermal stability of LiFePO4-based cathodes , 1999 .

[6]  J. Goodenough,et al.  Synthesis and structural characterization of the normal spinel Li[Ni2]O4 , 1985 .

[7]  John O. Thomas,et al.  Lithium extraction/insertion in LiFePO4: an X-ray diffraction and Mossbauer spectroscopy study , 2000 .

[8]  John B. Goodenough,et al.  Effect of Structure on the Fe3 + / Fe2 + Redox Couple in Iron Phosphates , 1997 .

[9]  S. Geller,et al.  Refinement of the structure of LiMnPO4 , 1960 .

[10]  J. Dahn,et al.  Thermal stability of LixCoO2, LixNiO2 and λ-MnO2 and consequences for the safety of Li-ion cells , 1994 .

[11]  Jackson,et al.  Atoms, molecules, solids, and surfaces: Applications of the generalized gradient approximation for exchange and correlation. , 1992, Physical review. B, Condensed matter.

[12]  Anton Van der Ven,et al.  Phase diagrams of lithium transition metal oxides: investigations from first principles , 1999 .

[13]  John B. Goodenough,et al.  Electrochemical extraction of lithium from LiMn2O4 , 1984 .

[14]  John B. Goodenough,et al.  LixCoO2 (0, 1980 .

[15]  I. Shinno,et al.  Next nearest neighbor effects in triphylite and related phosphate minerals. , 1997 .

[16]  K. S. Nanjundaswamy,et al.  Phospho‐olivines as Positive‐Electrode Materials for Rechargeable Lithium Batteries , 1997 .

[17]  Sai-Cheong Chung,et al.  Optimized LiFePO4 for Lithium Battery Cathodes , 2001 .

[18]  Peter Blaha,et al.  Full-potential, linearized augmented plane wave programs for crystalline systems , 1990 .

[19]  Schwarz,et al.  Determination of the nuclear quadrupole moment of 57Fe. , 1995, Physical review letters.

[20]  D. Peacor,et al.  The crystal structure of heterosite , 1972 .