Room temperature Solid-State Lithium-ion

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Room temperature Solid-State Lithium-ion

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Battery using LiBH

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-MgO composite Electrolyte

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Valerio Gulino,a)c) Matteo Brighi,b) Fabrizio Murgia,b) Peter Ngene,c) Petra de Jongh,c) Radovan 3

Černý,b)_{and Marcello Baricco}a)* 4

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a)_{Department of Chemistry and Inter-departmental Center Nanostructured Interfaces and Surfaces} 6

(NIS), University of Turin, Via Pietro Giuria 7, 10125 Torino, Italy 7

b)_{Laboratoire de Cristallographie, DQMP, Université de Genève, quai Ernest-Ansermet 24,} CH-8

1211 Geneva 4, Switzerland. 9

c)_{Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht} 10

University, Universiteitsweg 99, 3584 CG, Utrecht, The Netherlands 11 12 *Corresponding author 13 Marcello Baricco 14

E-mail address: [email protected] 15 Tel.: +39 011 6707569 16 Fax: +39 0116707856 17 18

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Supporting Information

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Figure S1: Nyquist plot of the synthetized samples 2

Table S1: EIS fitted values 3

Figure S2: PXD patterns of the synthetized samples 4

Figure S3: Enlargement of the Arrhenius plot of the synthetized samples 5

Figure S4: In situ EIS for Li|CE53|TiS2 working at 60 °C 6

Figure S5: GCPL of Li|CE26|TiS2 working at 60 °C 7

Figure S6: GCPL of the 65th cycle of Li|CE53|TiS2 at 60 °C and the 1st cycle of Li|CE53|TiS2 at RT 8

Figure S7: In situ EIS for Li|CE53|TiS2 working at RT 9

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Nyquist plot of the synthetized samples

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Figure S1. a) Impedance spectra shown on the Nyquist plot for the different LiBH4-MgO compositions at

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20 °C. b) Impedance spectra shown on the Nyquist plot for CE26 and CE53. The insets show the equivalent

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electrical circuits used to fit the data. Black lines correspond to the result of the fits.

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The equivalent electrical circuits used to fit the impedance data are shown in the insets of Figure 7

S1b. The bulk property was modelled with a CPEBulk in parallel with a resistor, representing the 8

Li-ion diffusion. A constant phase element (CPEElectrodes) was used to describe the non-ideal 9

diffusion between the blocking electrodes.1 The parameters obtained by the fit of the EIS data are 10 listed in Table S1. 11 12 Sample name Oxide fraction RBulk CPE

Bulk CPEElectrodes

wt. % v/v % Q n Q n

26CE 65 26 2.44 102_{1.01 10}-8 _0.75 _{2.53 10}-5 _0.56

53CE 85.7 53 1.55 102_{2.35 10}-9 _0.80 _{8.08 10-}7 _0.73

74CE 94.0 74 1.20 104_6.6010-9 _0.67 _{3.55 10}-7 _0.89

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Table S1. EIS fitted values of the spectra shown in Figure S1. The equivalent circuit adopted for the fit is 14

shown in Figure S1 inset.

15 16 17 18

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PXD patterns of the synthetized samples

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Figure S2. a) PXD patterns of LiBH4-MgO composites with different compositions. Circles: orthorhombic

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LiBH4; Squares: MgO.

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Figure S2 shows the Powder X-ray Diffraction (PXD) patterns of the as-prepared composites.

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The samples were characterized by X-ray powder diffraction (PXD) at RT using an Empyrean 7

PANalytical ( = CuKα1,2). Patterns were collected from 10° to 60° 2θ range, with a step size 0.016 8

and a time step of 60 s for a total of 30 min per scan. Glass capillaries were filled with the sample 9

powder and sealed under Ar atmosphere. 10

The presence of the Bragg peaks of the orthodromic LiBH4 is detected only for sample CE26, i.e. 11

for a pore filling higher than 100 %. 12

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Enlargement of the Arrhenius plot of the synthetized samples

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Figure S3. Li-ion conductivity of the second heating temperature-dependent EIS cycle of LiBH4-MgO

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composites with different compositions.

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In situ EIS for Li|CE53|TiS

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working at 60 °C

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Figure S4. a) Nyquist plot of Li|CE53|TiS2 cell before the first discharge. The inset shows the equivalent

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electrical circuit used to fit the data. RSSE is the electrolyte resistance, while R1 correspond to the contact

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resistance b) Contact resistance (R1) evolution obtained by in situ EIS for the same cell, plotted in

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logarithmic scale.

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Figure S4a shows the Nyquist plot before the first discharge cycle of the cell. The impedance

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spectra was fitted using the equivalent circuit shown in the inset. It was not possible to resolve the 10

SSE relaxation because of the limited instrumental high frequency range (20 kHz). Therefore, RSSE 11

accounts for the electrolyte and all the fast processes that can occur and its value was considered 12

constant during cycling. A second contibution to the circuit is present at lower frequency (labelled 13

R1) and it was assigned to the contact resistance. Figure S4b in ESI shows the evolution of the 14

contact resistance (R1) as a function of the charge/discharge cycles. 15

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GCPL of Li|CE26|TiS

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working at 60 °C

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2

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Figure S5. a) Voltage profiles of Li|CE26|TiS2 cell for a rate of C/50 (4.8 mA/g) at 60 °C. b) Discharge and

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charge capacity, Coulombic efficiency (discharge/charge capacity), and discharge capacity retention ratio

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(to the second discharge capacity) for the same cell.

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GCPL of the 65

th

_{cycle of Li|CE53|TiS}

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at 60 °C and the 1

st

cycle of Li|CE53|TiS

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at RT

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Figure S6. Voltage profiles of the 65th charge and discharge cycle of Li|CE26|TiS2 cell working at 60 °C and

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the 1st charge and discharge cycle of Li|CE26|TiS2 cell working at RT.

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In situ EIS for Li|CE53|TiS

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working at RT

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Figure S7. a) Nyquist plot of Li|CE53|TiS2 cell after the 65th discharge (red circles) and after 4 h of rest at

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RT (blue circles). b) Contact resistance (R1) evolution obtained by in situ EIS for the same cell at RT, plotted

5 in logarithmic scale. 6 7

References

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(1) E. Barsoukov, J. R. M. Impedance Spectroscopy: Theory, Experiment, and Applications, 9

Wiley and.; 2005. 10