Improved Electrochemical Performance of Li_1.25Ni_0.2Co_0.333Fe_0.133Mn_0.333O₂ Cathode Material Synthesized by the Polyvinyl Alcohol Auxiliary Sol-Gel Process for Lithium-Ion Batteries

Figure 1

SEM images of (a) a complete spherical shell, (b) broken MnO₂ hollow microspheres, and Li_1.25Ni_0.2Co_0.333Fe_0.133Mn_0.333O₂ samples for (c) x = 0.0 wt%, (d) x = 2.5 wt%, (e) x = 5.0 wt%, (f) x = 7.5 wt%, (g) x = 10.0 wt%, (h) x = 12.5 wt%, and (i) x = 15.0 wt%.

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