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Perspectives on Li and transition metal fluoride phosphates as cathode materials for a new generation of Li-ion batteries.

Antipov EV, Khasanova NR, Fedotov SS - IUCrJ (2015)

Bottom Line: Further advances in cathode materials are considered to lie in combining different anions [such as (XO4) (n-) and F(-)] in the anion sublattice, which is expected to enhance the specific energy and power of these materials.This review focuses on recent advances related to the new class of cathode materials for Li-ion batteries containing phosphate and fluoride anions.Special attention is given to their crystal structures and the relationships between structure and properties, which are important for their possible practical applications.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russian Federation.

ABSTRACT
To satisfy the needs of rapidly growing applications, Li-ion batteries require further significant improvements of their key properties: specific energy and power, cyclability, safety and costs. The first generation of cathode materials for Li-ion batteries based on mixed oxides with either spinel or rock-salt derivatives has already been widely commercialized, but the potential to improve the performance of these materials further is almost exhausted. Li and transition metal inorganic compounds containing different polyanions are now considered as the most promising cathode materials for the next generation of Li-ion batteries. Further advances in cathode materials are considered to lie in combining different anions [such as (XO4) (n-) and F(-)] in the anion sublattice, which is expected to enhance the specific energy and power of these materials. This review focuses on recent advances related to the new class of cathode materials for Li-ion batteries containing phosphate and fluoride anions. Special attention is given to their crystal structures and the relationships between structure and properties, which are important for their possible practical applications.

No MeSH data available.


Related in: MedlinePlus

BVS maps of Li+-ion migration in (a) the Li2CoPO4F structure and (b) the chemically oxidized Li1.3CoPO4F phase. Projections in the (101) and (110) layers are given. The inset indicates the alkali metal positions.
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fig7: BVS maps of Li+-ion migration in (a) the Li2CoPO4F structure and (b) the chemically oxidized Li1.3CoPO4F phase. Projections in the (101) and (110) layers are given. The inset indicates the alkali metal positions.

Mentions: These compounds, with an orthorhombic three-dimensional structure, can be prepared by direct synthesis. Li2NiPO4F was reported in 1999 (Dutreilh et al., 1999 ▶), while Li2CoPO4F (space group Pnma, with a = 10.444 Å, b = 6.381 Å, c = 10.864 Å and V = 724.1 Å3) was introduced in 2005 by Okada, who proposed to use it as a high-voltage cathode material (Okada et al., 2005 ▶). The structure type is built of MO4F2 octahedra linked through their edges to form rutile-like chains, with F atoms in trans-positions (Fig. 6 ▶). These parallel chains are interconnected through phosphate groups, and this packing creates a three-dimensional framework with large tunnels along the [010] direction which accommodate the Li ions in three distinct positions with full occupancy: two Li sites (Li1 and Li2) are five-coordinated, while the third one (Li3) has a distorted six-coordinated environment (Dutreilh et al., 1999 ▶; Hadermann et al., 2011 ▶). Analysis of the spatial distribution of BVS values using structure data obtained from combined neutron and X-ray diffraction data (Khasanova et al., 2015 ▶) suggested one-dimensional Li-ion diffusion along the [010] direction with de/intercalation of one Li ion per formula unit from the ‘most open’ Li1 site, while participation of the Li2 site located on the isosurface edge was found to be questionable (Fig. 7 ▶a).


Perspectives on Li and transition metal fluoride phosphates as cathode materials for a new generation of Li-ion batteries.

Antipov EV, Khasanova NR, Fedotov SS - IUCrJ (2015)

BVS maps of Li+-ion migration in (a) the Li2CoPO4F structure and (b) the chemically oxidized Li1.3CoPO4F phase. Projections in the (101) and (110) layers are given. The inset indicates the alkali metal positions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4285883&req=5

fig7: BVS maps of Li+-ion migration in (a) the Li2CoPO4F structure and (b) the chemically oxidized Li1.3CoPO4F phase. Projections in the (101) and (110) layers are given. The inset indicates the alkali metal positions.
Mentions: These compounds, with an orthorhombic three-dimensional structure, can be prepared by direct synthesis. Li2NiPO4F was reported in 1999 (Dutreilh et al., 1999 ▶), while Li2CoPO4F (space group Pnma, with a = 10.444 Å, b = 6.381 Å, c = 10.864 Å and V = 724.1 Å3) was introduced in 2005 by Okada, who proposed to use it as a high-voltage cathode material (Okada et al., 2005 ▶). The structure type is built of MO4F2 octahedra linked through their edges to form rutile-like chains, with F atoms in trans-positions (Fig. 6 ▶). These parallel chains are interconnected through phosphate groups, and this packing creates a three-dimensional framework with large tunnels along the [010] direction which accommodate the Li ions in three distinct positions with full occupancy: two Li sites (Li1 and Li2) are five-coordinated, while the third one (Li3) has a distorted six-coordinated environment (Dutreilh et al., 1999 ▶; Hadermann et al., 2011 ▶). Analysis of the spatial distribution of BVS values using structure data obtained from combined neutron and X-ray diffraction data (Khasanova et al., 2015 ▶) suggested one-dimensional Li-ion diffusion along the [010] direction with de/intercalation of one Li ion per formula unit from the ‘most open’ Li1 site, while participation of the Li2 site located on the isosurface edge was found to be questionable (Fig. 7 ▶a).

Bottom Line: Further advances in cathode materials are considered to lie in combining different anions [such as (XO4) (n-) and F(-)] in the anion sublattice, which is expected to enhance the specific energy and power of these materials.This review focuses on recent advances related to the new class of cathode materials for Li-ion batteries containing phosphate and fluoride anions.Special attention is given to their crystal structures and the relationships between structure and properties, which are important for their possible practical applications.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russian Federation.

ABSTRACT
To satisfy the needs of rapidly growing applications, Li-ion batteries require further significant improvements of their key properties: specific energy and power, cyclability, safety and costs. The first generation of cathode materials for Li-ion batteries based on mixed oxides with either spinel or rock-salt derivatives has already been widely commercialized, but the potential to improve the performance of these materials further is almost exhausted. Li and transition metal inorganic compounds containing different polyanions are now considered as the most promising cathode materials for the next generation of Li-ion batteries. Further advances in cathode materials are considered to lie in combining different anions [such as (XO4) (n-) and F(-)] in the anion sublattice, which is expected to enhance the specific energy and power of these materials. This review focuses on recent advances related to the new class of cathode materials for Li-ion batteries containing phosphate and fluoride anions. Special attention is given to their crystal structures and the relationships between structure and properties, which are important for their possible practical applications.

No MeSH data available.


Related in: MedlinePlus