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For enhancing the electrochemical properties of lithium transition-metal oxide, a novel core-shell structured cathode material LiNi Co Mn O @V O was designed and synthesized. The precursor of the material was made of metal hydroxide in the interior and metal 0.75 0.12 0.13 2 2 5 carbonate in the exterior, and with full concentration gradient structure. In this cathode material, the core was the high-Ni material, and the shell was the high-Mn material. The sphere material was coated and penetrated by V O due to the existence of pores. Furthermore, the material was 2 5 also doped by vanadium element. These were investigated and confirmed by X-ray diffraction, Focused Ion beam, EDS, TEM, etc. The 3 wt% V O-coated sample exhibited a remarkable cycling performance, with capacity retention of 86.5% at the current rate of 1 C after 100 cycles. 2 5 Besides, the rate capability of the V O-coated sample was obviously enhanced at high rates (2, 5 and 10 C). The interfacial charge transfer 2 5 resistance of the material after cycling was obviously decreased by V O coating. The cyclic voltammetry analysis showed that the interfacial 2 5 polarization of the material was inhibited due to V O coating.

Abundant material SnO2 is considered as a promising lithium‐ion battery (LIB) anode candidate due to its high theoretical capacity. Yet, the achieved capacity is restricted by the severe cycling degradation. Rational structural design can mitigate the volume expansion of SnO2, improving the structural stability and reaction kinetics at the same time. Herein, core‐shell structured SnO2@C/PEDOT : PSS microspheres are synthesized through a facile approach combined with hydrothermal treatment and polymerization. In the well‐designed architecture, amorphous carbon coated ultrafine SnO2 nanoparticles are aggregated into regular microspheres and wrapped by a PEDOT : PSS layer, forming a robust core‐shell structure with dual protection layers. Such hierarchical structure provides sufficient ion/electron ingress/transport channels, restrains the adverse reaction of the electrolyte, improves the conductivity and buffers the interior stress of the entire electrode, resulting in the stable cycle performance. When evaluated as LIB anode, it demonstrates an initial reversible capacity of 1170.5 mAh g−1 at 0.1 C, maintaining a high capacity of 441.5 mAh g−1 after 1200 stable cycles at high rate of 2 C. The strategy gives a rational avenue to design the oxide anodes with efficient hierarchical structure for LIB development.

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