Crystalline defects, lithium

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 deposition points are the pits on the lithium anode caused by discharge. Crystalline defects and the grain boundaries in lithium may also initiate deposition. 

After the fiber-like lithium has grown, lithium is still deposited on the lithium substrate that is not at the tip of the fiber-like lithium. If the deposition continues for a long time, the lithium electrode becomes covered with long, fiber-like lithium. In this situation, lithium-ion transport in the electrolyte to the lithium electrode surface is hindered by the fiber-like lithium. Then, lithium begins to be deposited on the tip and on kinks of the fiber-like lithium, where there are crystalline defects. The morphology of the deposited lithium is particle-like or amorphous. As there are many kinks, the current density of the lithium deposition becomes very low. This low current density may create particle-like, rather than fiber-like, lithium. Thus the morphology of the lithium as a whole becomes mushroom-like [31]. 

For Co, the energy of /JS-(Li jCo)tet(LijX2o3)oct08 by contrast never drops below that of l-l iJZoOz- The results of Figure 8 for crystalline structures, like those in Table 1, mimic the results of the tetrahedral defect calculations (Figure 4). In each case tetrahedral Co is found to be unfavorable at all lithium concentrations and oxidation states considered, while tetrahedral Mn is found to be favorable at the Lii/2Mn02 composition when it has a -1-2 valence. 

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