READ ME File For Dataset to support the article "La and Nb co-doped BaTiO3 film with positive-temperature-coefficient of resistance for thermal protection of batteries"

Dataset DOI: https://doi.org/10.5258/SOTON/D2206

Date that the file was created: May, 2022

Authors: Min Zhang, Sacha Fop, Denis Kramer, Nuria Garcia-Araez and Andrew L. Hector

Licenses/restrictions placed on the data, or limitations of reuse:CC BY

This dataset supports the publication:
AUTHORS:Min Zhang, Sacha Fop, Denis Kramer, Nuria Garcia-Araez and Andrew L. Hector
TITLE:A La and Nb co-doped BaTiO3 film with positive-temperature-coefficient of resistance for thermal protection of batteries
JOURNAL:Journal of Materials Chemistry A
PAPER DOI IF KNOWN: 10.1039/D2TA00998F

This dataset contains:

All data in CSV format, contents described below:

Fig. 1 a. XRD patterns of undoped, La-doped, Nb-doped and La-Nb-co-doped BaTiO3 samples; enlarged XRD patterns to highlight the shift in the peak position and the split of 101/110 reflections (middle); enlarged XRD patterns of the split of 200/002 reflections (right). b. Lattice parameters (a, c) and tetragonality (c/a) against samples with various doping elements and amounts (sample labels explained in Table 1).

Fig. 2 a. Raman spectra of undoped, La-doped, Nb-doped and La-Nb-co-doped BaTiO3 samples (peaks at ~307 cm-1 being marked as shaded). b. Relative integrated intensities of the Raman peak at 307 cm-1, as a function of BaTiO3 samples with various doping elements and amounts (sample labels explained in Table 1).

Fig. 3 a. SEM images of BTO, BTO-L3, BTO-N2, BTO-L3N2 samples. b. Average BaTiO3 grain sizes determined from SEM images, as a function of various doping elements and amounts. c. Room-temperature conductivity and PTCR effect of undoped, La-doped, Nb-doped and La-Nb-co-doped BaTiO3 samples (sample labels explained in Table 1).

Fig. 4 a. Cyclic voltammetry at scan rate of 0.1 mV s-1 and b. 0.1C galvanostatic charge/discharge plots of LiFePO4 half cells with and without the PTCR film at 25 °C; c. 0.1C galvanostatic charge/discharge plots and d. electrochemical impedance spectroscopy of batteries with and without the PTCR film at 25 °C and elevated temperatures of 135 °C and 150 °C.

Fig. 5 Electrochemical performances of LiFePO4 half cells with and without the PTCR film: galvanostatic cycling performances and charge/discharge plots (insets) at a current rate of a. 0.1C and b. 1C at 25 °C; c. the specific discharge capacities at various sequential rates from 0.1C to 5C at 25 °C; d. galvanostatic cycling performances and charge/discharge plots (inset) at a current rate of 1C at 45 °C.

Fig. 6 a. Voltage changes during overcharging tests for LiFePO4-graphite cells with and without the BTO-L3N2 PTCR film; b. temperature dependence of resistivity (PTCR effect) for the BTO-L3N2 film; c. voltage and temperature changes during heating tests at 150 °C for LiFePO4-graphite cells with and without the BTO-L3N2 PTCR film; d. distribution diagram of the survival time of cells during heating tests, insets are the cells without (left) and with (right) the PTCR film, photographs being taken after heating tests.


Fig. S1 Rietveld fits to the XRD patterns of a. BTO, b. BTO-L3, c. BTO-L6, d. BTO-L9, e. BTO-N2, f. BTO-N4, g. BTO-N6, h. BTO-L3N2, i. BTO-L3N4, j. BTO-L3N6 samples (sample labels explained in Table 1). The data points and Rietveld fits were overlaid as black crosses and red lines, respectively. The difference plots were shown in blue. The pink marks showed allowed reflection positions for tetragonal BaTiO3 structure with space group P4mm.

Fig. S2 SEM images of a. BTO, b. BTO-L3, c. BTO-L6, d. BTO-L9, e. BTO-N2, f. BTO-N4, g. BTO-N6, h. BTO-L3N2, i. BTO-L3N4, j. BTO-L3N6 samples (sample labels explained in Table 1); inserted patterns to show the grains sizes of the samples determined using ImageJ software, and the size distributions analysed with a Gaussian function.

Fig. S3 Current-voltage plots (3 cycles each) for a. BTO, b. BTO-L3, c. BTO-L6, d. BTO-L9, e. BTO-N2, f. BTO-N4, g. BTO-N6, h. BTO-L3N2, i. BTO-L3N4, j. BTO-L3N6 samples, cycling at scanning rate of 20 mV s-1, showing the ohmic behaviour of the samples (sample labels explained in Table 1).

Fig. S4 0.1C galvanostatic charge/discharge plot of lithium-ion battery with the PTCR film when the temperature was set back to 25 °C, after the thermal treatment at 135 °C shown in Fig. 4c.

Fig. S5 Electrochemical performances of LiFePO4 half cells with and without the PTCR film: Coulombic efficiency vs. cycle number at a current rate of a. 0.1C and b. 1C at 25 °C; c. galvanostatic cycling performances and charge/discharge plots (inset) at a current rate of 0.5C at 25 °C; d. Coulombic efficiency vs. cycle number at a current rate of 0.5C at 25 °C; e. the charge/discharge plots at various sequential rates from 0.1C to 5C at 25 °C; f. Coulombic efficiency vs. cycle number at a current rate of 1C at 45 °C.

Fig. S6 Comparison of electrochemical performances of LiFePO4 half cells with and without the PTCR film: the specific discharge capacities in the initial cycle, capacity retentions and Coulombic efficiencies after 50 cycles at a current rate of a. 0.1C and b. 1C at 25 °C. Error bars show the differences in repeat experiments.

Fig. S7 Electrochemical performances of LiCoO2 half cells with and without the PTCR film: galvanostatic cycling performances and charge/discharge plots (inset) at a current rate of 0.1C at 25 °C.

Fig. S8 a. Cyclic voltammetry plots of battery with the BaTiO3-based PTCR film as cathode and Li as anode at 20 mV s-1 over the range of 2.5 to 4.1 V for 1000 cycles; b. charge/discharge plots of battery with PTCR film as cathode and Li as anode under galvanostatic cycling between 2.5 and 4.1 V for 1000 cycles. c. comparison of the cyclic voltammograms measured with the BaTiO3-based PTCR film in a and the cyclic voltammograms measured with LiFePO4 cathodes in Fig. 4a.

Fig. S9 Voltage changes during overcharging tests for LiCoO2-graphite cells with and without the BTO-L3N2 PTCR film.

Fig. S10 Current-voltage plots (3 cycles each) for BTO-L3N2 sample at different temperatures from 25 to 150 °C, cycling at scanning rate of 20 mV s-1, showing the ohmic behaviour of the sample (sample label explained in Table 1). Note that the blue and green lines are coincident with the cyan line, and the red line is coincident with the orange line.

Fig. S11 Voltage and skin temperature changes during heating tests at 150 °C for LiFePO4-graphite full cells a. without and b. with the BTO-L3N2 PTCR film.

Fig. S12 Voltage and temperature changes during heating tests at 150 °C for LiCoO2-graphite cells with and without the BTO-L3N2 PTCR film.