Host dimensionality Oregon State University1

2 Intercalate type

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

Intercalation/exfoliation Graphite exfoliation Layered chalcogenide exfoliation Can we make colloidal [graphenium] + or [graphide] - sheets

…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

6 Graphite structure C-C in-plane = 1.42 Å Usually (AB) n hexgonal stacking Interlayer distance = Å A B A Graphite is a semi-metal, chemically stable, light, strong

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

8 Selected rechargeable batteries C. Pillot, BATTERIES 2009, Cannes, 2009

9 Graphite Lithiation Graphite lithiation:approx 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

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

Next decade projections 11 Telsa battery pack m

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 -

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

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

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, % hydrofluoric acid, ambient conditions 2. hexane, air dry Oxidant and anion source are separate and changeable. Surprising stability in 50% aqueous acid.

Oregon State University16 C x N(SO 2 CF 3 ) 2 chem prepn

New syntheses: N(SO 2 CF 3 ) 2 orientation FFFF

Increasing F anion co-intercalate with reaction time C x N(SO 2 CF 3 ) 2 ·  F Katinonkul, Lerner Carbon (2007)

New syntheses: imide intercalates Anion mw d i / nm 1. N(SO 2 CF 3 ) N(SO 2 C 2 F 5 ) N(SO 2 CF 3 )(SO 2 C 4 F 9 )

Oregon State University20 C x N(SO 2 CF 3 ) 2 echem prepn 2  1 3  2

Oregon State University21 C x N(SO 2 CF 3 ) 2 - echem prepn C x PFOS C x N(SO 2 CF 3 ) 2

Oregon State University22 Imide (NR 2 - ) intercalates Anion MW d i / Å N(SO 2 CF 3 ) N(SO 2 C 2 F 5 ) N(SO 2 CF 3 ) (SO 2 C 4 F 9 )

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

Oregon State University24 C x PFOS intercalate structure Anions self- assemble as bilayers within graphite galleries

New syntheses: C x SO 3 C 8 F 17 Domains are sheets along stacking direction

nm C x B(O 2 C 2 O(CF 3 ) 2 ) 2 Stage 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