Shell spinel LiNi[Formula: see text]Mn[Formula: see text]O4 hollow microspheres were successfully synthesized by MnCO3 template, and characterized by XRD, SEM, and TEM. The results show that the hollow LiNi[Formula: see text]Mn[Formula: see text]O4 cathode has good cycle stability to reach 124.5, 119.8, and 96.6[Formula: see text]mAh/g at 0.5, 1, and 5 C, the corresponding retention rate of 98.1%, 98.2%, and 98.0% after 50 cycles at 20[Formula: see text]C, and the reversible capacity of 94.6[Formula: see text]mAh/g can be obtained at 1 C rate at 55[Formula: see text]C, 83.3% retention after 100 cycles. As the temperature decreases from 10[Formula: see text]C to [Formula: see text]C, the resistance of [Formula: see text] increases from 5.5 [Formula: see text] to 135 [Formula: see text], [Formula: see text] from 27 [Formula: see text] to 353.2 [Formula: see text], and [Formula: see text] from 12.7 [Formula: see text] to 73.0 [Formula: see text]. Moreover, the B constant and [Formula: see text] activation energy are 4480[Formula: see text]K and 37.22[Formula: see text]KJ/mol for the NTC spinel material, respectively.
SnO2/polypyrrole hollow spheres with improved cycle stability as lithium-ion battery anodes
