The effects of Al-doped to cathode material based on hollow microspheres of nickel-manganese on sodium-ion batteries

Sodium-ion batteries (SIBs) are expected to be a great substitute for lithium ion batteries. Although there are many difficulties to overcome, SIBs have become one of the most important research areas for large-scale energy storage equipment. The spherical particles are conducive to the contact between the cathode material and the electrolyte, which could increase the electrochemical reaction area, and improve the deintercalation rate of sodium ions during charging and discharging. In this paper, a precipitation method was used to prepare spherical MnCO3material as template and raw material. After all the raw materials were weighed with the molar ratios of Na0.67Mn0.67-0.75xNi0.33AlxO2, a series of hollow micro-spherical sodium-ion cathode materials were synthesized by the conventional high-temperature solid-state method. The effects of Al-doped on the structure and electrochemical performance of Na0.67Ni0.33Mn0.67O2was studied, and it was founded that the samples doped with Al had smaller particle size than that without Al. The electrochemical tests showed that Na0.67Mn0.595Ni0.33Al0.1O2(x= 0.1) exhibite superior high-rate capabilities and cyclic stability. And the hollow microsphere structure has a higher capacity, the first discharge capacity at 0.1C reach 128 mAh g-1.