A Highly Reversible Lithium Metal Anode

Transcription

1 SUPPLEMENTARY INFORMATION A Highly Reversible Lithium Metal Anode Min Sik Park 1,,*, Sang Bok Ma 1,, Dong Joon Lee 1, Dongmin Im 1,*, Seok-Gwang Doo 1, Osamu Yamamoto 2 1 Energy Lab., Samsung Advanced Institute of Technology, Samsung Electronics, 130 Samsung-ro, Suwon, Gyeonggi-do , Republic of Korea 2 Department of Chemistry, Mie University, Tsu , Japan Both authors contributed equally to this work. * ms91.park@samsung.com, dongmin.im@samsung.com 1

2 Supplementary Table S1. Details of the calculation of the energy densities and estimated driving distances for Li-ion, Li-S, and Li-air battery cells. Li-Ion Battery Li-Metal Battery Component Unit Graphite-LiCoO 2 Li-S Li-Air a weight of current collector (W PC) mg cm -2 Positive Electrode Negative Electrode Separator and Electrolyte Battery Cell areal capacity (C PA) variable mah cm -2 b specific capacity (C PS) mah g -1 ratio of electro-active material in electrode (R P) weight of electrode material (W PE) 1000 C PA / (C PS R P) mg cm -2 c weight of current collector (W NC) 3.58 mg cm -2 d NP ratio (R NP) areal capacity (C NA) R NP C PA mah cm -2 e specific capacity (C NS) mah g -1 ratio of electro-active material in electrode (R N) weight of electrode material (W NE) 1000 C NA / (C NS R N) mg cm -2 f weight of separator (W S) 1.00 mg cm -2 g weight of protective layer (W L) mg cm -2 h weight of electrolyte (W E) 0.2 (W PE + W NE + W S) mg cm -2 areal capacity (C CA) C PA mah cm -2 i voltage (V C) V weight of battery cell (W C) W PC + W PE + W NC + W NE + W S + W L + W E mg cm -2 energy density of battery cell without packing components (E WOP) C CA V C / W C Wh kg -1 j estimated energy density of battery cell with packing components (E C) 0.6 E WOP Wh kg -1 k estimated driving distance of electric vehicle (D EV) 1.14 [km/(wh kg -1 )] E C km Driving distance a weight of current collector (W PC) = the half weight of a 12 μm thick Al foil for the Li-ion and Li-S batteries, and the half weight of the gas-diffusion layer (SIGRACET GDL25BA) for the Li-air battery foil, owing to it being coated on both sides with electrode materials. b specific capacity (C PS) = the actual capacity, based on the weight of LiCoO 2, and the sulfur and carbon materials in the positive electrode, for the Li-ion, Li-S, and Li-air batteries, respectively. c weight of current collector (W NC) = the half weight of an 8 μm thick Cu foil, owing to it being coated on both sides with electrode materials, for the Li-ion, Li-S, and Li-air batteries. d NP ratio (R NP) = the areal capacity of the negative electrode divided by the areal capacity of the positive electrode. e specific capacity (C NS) = the actual capacity of graphite with respect to Li-ion batteries and the theoretical capacity of lithium with respect to Li-S and Li-air batteries. f weight of separator (W S) = the weight of Celgard 3501 g weight of protective layer (W L) calculated using the assumption that the protective layer is the Li-ion conducting glass ceramic film having a thickness of 30 μm and a density of 2.96 g cc -1. h weight of electrolyte (W E) calculated under the assumption that the weight of the electrolyte is 20% of the total weight of the positive and negative electrode materials and that of the separator. i voltage (V C) = the actual potentials of the electrochemical reactions for the insertion of Li into Li xcoo 2, the formation of Li 2S, and the formation of Li 2O 2 in Li-ion, Li-S, and Li-air batteries, respectively. j estimated energy density of a battery cell with packing components (E C), calculated under the assumption that the battery cell with packing components is 1.67 times heavier than it was before being packed. k estimated driving distance of an electric vehicle (D EV), calculated using on the basis of the car Nissan Leaf, which uses Li-ion battery cells 3 with an energy density of 140 Wh kg -1 and has a driving range of 160 km. 2

3 Supplementary Table S2. Lists of the candidate solvents and those screened computationally. Aprotic protophilic solvents (14 4) Candidate solvents (49) Triethylamine, Hexamethylphosphoric triamide, N,N-diethylacetamide, Tetramethylurea, N,N-diethylformamide, N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, 3-Methyl-2-oxazolidinone, Dimethyl sulfoxide, N,N-dimethylformamide, Pyridine, Quinoline, Sulfolane, 3-Methyl sydnone Screened solvents with a reduction potential lower than that of lithium (22) Triethylamine, Hexamethylphosphoric triamide, N,N-diethylacetamide, Tetramethylurea Aprotic protophobic solvents (19 2) Lowpermittivity electron donor solvents (16 16) Diethyl carbonate, Dimethyl carbonate, Ethyl acetate, Methyl acetate, Ethyl formate, Propionitrile, Acetonitrile, Methyl formate, γ-butyrolactone, Trimethyl phosphate, 3-Pentanone, 2-Butanone, Acetone, Acetic anhydride, Benzonitrile, Acetophenone, Diethyl sulfide, Ethylene glycol sulfite, Nitromethane 1,4-Dioxane, 1,2-Dimethoxyethane, Diethyl ether, Diglyme, Triglyme, Tetrahydropyran, Diisopropyl ether, Polyglyme, Tetraglyme, 1,3-Dioxolane, Tetrahydrofuran, 2,5-Dimethyltetrahydrofuran, 2,2-Dimethyltetrahydrofuran 2-Methyltetrahydrofuran, o-dimethoxybenzene, Anisole Diethyl carbonate, Dimethyl carbonate 1,4-Dioxane, 1,2-Dimethoxyethane, Diethyl ether, Diglyme, Triglyme, Tetrahydropyran, Diisopropyl ether, Polyglyme, Tetraglyme, 1,3-Dioxolane, Tetrahydrofuran, 2,5-Dimethyltetrahydrofuran, 2,2-Dimethyltetrahydrofuran 2-Methyltetrahydrofuran, o-dimethoxybenzene, Anisole 3

4 Supplementary Table S3. Boiling point and solubility of Li salt (LiBF 4) of computationally screened electrolytes. 11 solvents exhibiting solubilities of more than 1.0 M for LiBF 4 salt were screened (yellow letters). Solvent Boiling point ( o C) Solubility of LiBF 4 (M) 1,4-dioxane 101 less than 0.5 Triethylamine 89 X 1,2-dimethoxyethane 85 at least 1.0 Diethyl ether 35 less than 0.5 Diglyme 162 at least 1.0 Triglyme 216 less than 0.5 Tetrahydropyran 88 at least 1.5 Diisopropyl ether 69 less than 0.5 Polyglyme - at least 1.0 Tetraglyme 275 at least 1.5 1,3-dioxolane (solidification) Tetrahydrofuran 66 at least 1.5 2,5-dimethyltetrahydrofuran - at least 1.0 2,2-dimethyltetrahydrofuran - at least methyltetrahydrofuran 80 at least 1.5 Hexamethylphosphoric triamide 206 X o-dimethoxybenzene 233 X Diethyl carbonate 126 at least 1.5 Anisole 154 less than 0.5 Dimethyl carbonate 90 at least 1.5 Tetramethylurea 177 X * Computationally screened N,N-diethylacetamide solvent is excluded, since it is classified as a toxic chemical. 4

5 Supplementary Table S4. Comparison of the theoretically determined reduction potentials of various solvents using different DFT levels with those obtained experimentally. (unit : V vs. aq. SHE) B3LYP B3LYP B3LYP B3LYP B3LYP HF B3LYP Exp. Theory Level Basis Set 6-31G(d) 6-31G(d) 6-31G(d) 6-31G(d) 6-31G(d) GEN (+diffuse) G(d,p) - Solvation Model ONSAGER IPCM CPCM SCIPCM PCM PCM PCM - Solvents Molecules 1,4-Benzoquinone Benzophenone Nitrobenzene Cyclohexanone

6 Supplementary Figure S1. a,b, Supercell geometry of the interface between the surface of the Li electrode and the solvent molecules after 1 ps, c,d, local structure showing the interaction between a surface Li atom and a solvent molecule, for THF ((a) and (c)) and for 1,3-dioxolane ((b) and (d)). The green, red, brown, and pink spheres represent lithium, oxygen, carbon, and hydrogen atoms, respectively. 6

7 Supplementary Figure S2. Interfacial energies between Li metal and the solvents THF, 2-methyl THF, 2,2-dimethyl THF, and 2,5-dimethyl THF. The red, grey, and white spheres represent oxygen, carbon, and hydrogen atoms, respectively. 7

8 Supplementary Figure S3. The in situ Li symmetric cell used to directly observe the growth of lithium dendrites. 8

9 References 1. Bard, A. J. & Faulkner, L. R. Electrochemical Methods: Fundamentals and Applications (Wiley, 2000). 2. Lide, D. R. CRC Handbook of Chemistry and Physics, 87 th Edition (Taylor & Francis, 2006). 9