Page 411 - Handbook of Battery Materials

13.5 Morphology of Deposited Lithium 383

1.0 µm
Figure 13.1 Morphology of lithium deposited on
−2
−2
stainless steel, 3 mA cm ,3mAh cm ,1.5mol L −1
LiAsF 6 –EC/2MeTHF (1 : 1), v/v.
A possible mechanism for lithium deposition based on our observations of
lithium morphology in LiAsF 6 –EC/2MeTHF electrolyte is described below [31].
Figure 13.2a shows our image of the mechanism.

1) Lithium is deposited on a lithium anode under the protective film without
serious damage to the film.
2) The deposition points on the lithium electrode are the points at which the
protective film has a higher lithium-ion conductivity. One example of these

Li + +
Li anode Li
Li +
+
Li
Li + Li +
Li anode
Li anode
+ +
Li Li
Li +
Li +
Li anode
Li anode
Li + Li +
Li +
Li + Dead lithium

Li anode
Li anode
Lithium deposition Lithium dissolution

Figure 13.2 A possible mechanism for lithium deposition
(a) based on dissolution (b) lithium morphology observa-
tions in LiAsF 6 –EC/2MeTHF electrolyte.