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Date of download: 10/24/2017 Copyright © ASME. All rights reserved.

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1 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: Schematic of the one-dimensional (1D) electrochemical model in the x-direction of the battery based on the Newman's model. Intercalation of lithium ions is illustrated by small beads. Solid particle's sizes in the electrodes can be same or different. Electrolyte exists in all battery domains while solid particles exist only in electrodes.

2 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: (a) Equilibrium potential of the LixC6 and (b) LiyCoO2 versus the state of the charge of electrode. Curves of ∂U/∂T for the negative electrode (c) and the positive electrode (d). Dots are the start points of charge and discharge which are summarized with C and D [9]. All data extracted from Ref. [9] are to be used in the simulation of the current paper.

3 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: Bulk ionic conductivity (a) and bulk salt-diffusion coefficient (b) as a function of concentration [9]

4 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: Comparison between the model proposed in Ref. [9], which is shown with continuous lines, and the model constructed in the current paper according to the parameters used in Ref. [9], which are shown with circle and rectangle markers. Simulations were done for applied discharge currents of 0.5 and 1 C-rates. A cutoff voltage of 3.3 V was considered in the simulations. In a wide range of the battery discharge, the maximum difference between results of Ref. [9] and our simulation was about 1.5%. The maximum difference occurs in the voltages below 3.5 V, which has an amount of 3%.

5 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: Charge curves for the size 1(a) and size 5(c) in Table 3 at different C-rates. Discharge curves of size 1(b) and size 5(d) in Table 3 at different C-rates. At a specified C-rate, the cell voltage is plotted versus the charge and discharge capacity of the battery. For the charge process, a cutoff voltage of 4.5 V is considered and for the discharge process the cutoff voltage of 3.3 is considered for the end of the process in simulations.

6 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: Reversible heat (a) and irreversible heat (b) versus discharge capacity of the battery at different C-rates for size 5 in Table 3. Two heating and cooling zones exist for reversible heat while irreversible heat is positive in the whole range of the battery discharge. At high C-rates, irreversible heat drastically increases because it is a function of applied current with a power of two.

7 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: Maximum reversible heat in charge (MRH-C) (a) and discharge (MRH-D) (b) for different sizes and C-rates. The maximum amounts were extracted from the curves similar in Fig. 6. At low C-rates, size changes have no noticeable change in MRH. At 5 C-rate in the charge process, there is no heating and therefore there is no maximum heating value. Too fast charging leads to have only the zone of cooling in 5 C-rate.

8 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: MRC in charge (a) and discharge (b) for the sizes in Table 3. There is no noticeable change in MRC for both charge and discharge cycles with the increase of the solid particles size while increases with the increase of C-rate.

9 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: Maximum irreversible heat (MIrH-C) (a) in charge and discharge (b) for the sizes in Table 3. There are ascending curves for both charge and discharge cases. Irreversible heat drastically increases with the increase of C-rate since it originates from internal resistances in a battery. These resistances are a function of applied current with a power of two.

10 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: Overpotential curves in charge (a) and discharge (b) for the sizes in Table 3. Voltage cell initially increases in charging while decreases in discharging.

11 Date of download: 10/24/2017 Copyright © ASME. All rights reserved. From: Numerical Study of Composite Electrode's Particle Size Effect on the Electrochemical and Heat Generation of a Li-Ion Battery J. Nanotechnol. Eng. Med. 2016;6(4): doi: / Figure Legend: Maximum capacity of the battery during charging (a) and discharging (b) at different C-rates for the sizes in Table 3. Maximum capacity decreases with the increase of solid particle's sizes. As the size increases, although the surface area of the solid particles increases, the active surface area for electrochemical decreases, hence, the maximum capacity decreases with increasing the sizes.


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