Page 454 - Handbook of Battery Materials

426 14 Lithium Alloy Anodes

(a)
0.05 0.39
40 mA/cm 2
0.04 0.38

0.03 2 0.37
20 mA/cm
0.02 10 mA/cm 2 0.36
5 mA/cm 2
0.01 0 Si – Li 171 Si plateau (OCV) 0.35
polarization , (V) -0.01 10 mA/cm 2 2 0.33 potential vs Li (V)
0.34
5 mA/cm
0.32
-0.02
-0.03 20 mA/cm 2 0.31
-0.04 40 mA/cm 2 0.30
-0.05 charging 0.29
0.28
-0.06
0 10 20 30 40 50 60 70 80 90 100
charge stored as % of capacity
(b)
0.39
0.05
0.38
0.04
0.37
0.03 I = 40 mA/cm 2
0.36
0.02
0.35
0.01
polarization , (V) -0.01 Si – Li 171 0.34 potential vs Li (V)
Si plateau (OCV)
0
0.33
0.32
-0.02
0.31
-0.03 charging
0.30
-0.04
0.29
-0.05
0.28
0 10 20 30 40 50 60 70 80 90 100
charge stored as % of capacity
Figure 14.14 Charge-discharge curves for the upper plateau
in the Li x Si system inside a matrix of the Li 2.6 Sn → phase
◦
at 415 C. (a) Effect of current density. (b) The potential
overshoot related to the nucleation of the second phase is
mostly eliminated if the electrode is not cycled to the ends
of the plateau [48].