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Host dimensionality Oregon State University1
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2 Intercalate type http://www.cem.msu.edu/~pinnweb/research-na.htm
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Single-sheet inorganic colloidal dispersions are common and easily prepared Ion exchange: (fixed charge density) smectite clays Na x+y Al 2-y Mg y Si 4-x Al x O 10 (OH) 2 layered double hydroxides Mg 3 Al(OH) 8 Cl layered oxides Cs x Ti 2-x/4 x/4 O 4 metal phosphorous sulfides K 0.4 Mn 0.8 0.2 PS 3 Redox reaction: (variable charge density) metal dichalocogenidesLi x MoS 2 layered oxidesLi x CoO 2, Na x MoO 3
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Intercalation/exfoliation Graphite exfoliation Layered chalcogenide exfoliation Can we make colloidal [graphenium] + or [graphide] - sheets
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…if you have the correct sheet charge density and an appropriate polar solvent Intercalation compound Swollen Colloidal No solvation solvent in galleries solvated ions/sheets L > solv solv > L higher surface charge density lower surface charge density
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6 Graphite structure C-C in-plane = 1.42 Å Usually (AB) n hexgonal stacking Interlayer distance = 3.354 Å http://www.ccs.uky.edu/~ernst/ A B A Graphite is a semi-metal, chemically stable, light, strong
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7 Li ion battery chemistry Cathode LiCoO 2 Li 1-x CoO 2 + xLi + + xe - Anode 6C + Li + + e - C 6 Li Electrolyte Organic solvent with LiPF 6
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8 Selected rechargeable batteries C. Pillot, BATTERIES 2009, Cannes, 2009
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9 Graphite Lithiation Graphite lithiation:approx 0.2-0.3 V vs Li + /Li Theoretical capacity: Li metal> 1000 mAh/g C 6 Li 370 Actual C 6 Li formation: 320 – 340 mAh/g reversible; 20 – 40 irreversible Expands about 10% along z
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10 Theoretical capacity: Li metal> 1000 mAh/g C 6 Li 370 Typical C 6 Li formation:320 – 340 reversible; 20 – 40 irreversible Li arrangement in C 6 Li Li + occupies hexagon centers of non-adjacent hexagons
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Next decade projections 11 Telsa battery pack http://www.teslamotors.co m
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Oregon State University12 GIC’s Reduction M + C x - Group 1 except Na Oxidation C x + An - F, Br 3 -, O (OH) BF 4 -, P BiF 6 -, GeF 6 2- to PbF 6 2-, MoF 6 -, NiF 6 2-, TaF 6 -, Re PtF 6 - SO 4 -, NO 3 -, ClO 4 -, IO 3 -, VO 4 3-, CrO 4 2- AlCl 4 -, GaCl 4 -,FeCl 4 -, ZrCl 6 -,TaCl 6 -
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Oregon State University13 Staging and dimensions I c = d i + (n - 1) (3.354 Å) For fluoro, oxometallates d i ≈ 8 A, for chlorometallates d i ≈ 9-10 A
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Oregon State University14 Graphite oxidation potentials H 2 O oxidation potential vs Hammett acidity Colored regions show the electrochemical potential for GIC stages. 49% hydrofluoric acid All GICs are unstable in ambient atmosphere, they oxidize H 2 O
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New syntheses: chemical method N S O O CF 3 S O O F3CF3C.. C x + K 2 MnF 6 + LiN(SO 2 CF 3 ) 2 C x N(SO 2 CF 3 ) 2 + K 2 LiMnF 6 oxidant anion source GIC 1,2 1. 48% hydrofluoric acid, ambient conditions 2. hexane, air dry Oxidant and anion source are separate and changeable. Surprising stability in 50% aqueous acid.
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Oregon State University16 C x N(SO 2 CF 3 ) 2 chem prepn
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New syntheses: N(SO 2 CF 3 ) 2 orientation FFFF
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Increasing F anion co-intercalate with reaction time C x N(SO 2 CF 3 ) 2 · F Katinonkul, Lerner Carbon (2007)
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New syntheses: imide intercalates Anion mw d i / nm 1. N(SO 2 CF 3 ) 2 280 0.81 2. N(SO 2 C 2 F 5 ) 2 380 0.82 3. N(SO 2 CF 3 )(SO 2 C 4 F 9 ) 430 0.83 1 2 3
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Oregon State University20 C x N(SO 2 CF 3 ) 2 echem prepn 2 1 3 2
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Oregon State University21 C x N(SO 2 CF 3 ) 2 - echem prepn C x PFOS C x N(SO 2 CF 3 ) 2
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Oregon State University22 Imide (NR 2 - ) intercalates Anion MW d i / Å N(SO 2 CF 3 ) 2 280 8.1 N(SO 2 C 2 F 5 ) 2 380 8.2 N(SO 2 CF 3 ) 430 8.3 (SO 2 C 4 F 9 )
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Oregon State University23 C x PFOS - preparation C x + K 2 Mn(IV)F 6 + KSO 3 C 8 F 17 C x SO 3 C 8 F 17 + K 3 Mn(III)F 6 (C x PFOS) Solvent = aqueous HF 3.35 A
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Oregon State University24 C x PFOS intercalate structure Anions self- assemble as bilayers within graphite galleries
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New syntheses: C x SO 3 C 8 F 17 Domains are 10-20 sheets along stacking direction
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1.12 0.78 nm C x B(O 2 C 2 O(CF 3 ) 2 ) 2 Stage 2 1.13 0.85 nm Stage 1 C x B(O 2 C 2 (CF 3 ) 4 ) 2 Borate chelate GIC’s Blue: obs Pink: calc Unexpected anion orientation - long axis to sheets T
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