Preparation And Electrochemical Performances Of High Capacity Electrode Materials For Lithium Ion Battery

Lithium-ion batteries have been successfully applied in portable electronics and are developing to the application in the fields of electric vehicles and energy storage devices owning to their high energy densities, long cycle life and no memory effect.However, current lithium-ion battery technologies are still far from the satisfactory to meet the increasingly demands above. It is of great importance to explore novel cathodes and anodes in order to advance battery technologies. In this paper, according to the in-depth review of the high capacity lithium rich (LR-MNC, with an available capacity of > 250 mAh g-1) cathode and nickel oxide (NiO, with a theoretical capacity of 718 mAh g-1) anode, Li1.2Ni0.13Co0.13Mn0.54O2 based on a carbonate co-precipitation method and its doping modification were investigated, and 1D hollow NiO synthesized by a microemulsion-assisted method and its electrochemical performances were also researched. The main points are summarized as follows.On account of the drawbacks of capacity fade, voltage decay and poor rate capability and thermal stability for LR-MNC, the mono-doping and co-doping modification of Al and F for Li1.2Ni0.13Coo.13Mn0.54O2 porous sphere cathodes prepared via a co-precipitation reaction and a subsequent solid phase calcination were studied. Al&F co-doping combines the advantages of both Al-doping and F-doping, which effectively restrains the layered-to-spinel phase transformation, and as a consequence, inhibits the capacity fade and voltage decay: delivering a discharge capacity of 217 mAh g-1 with retention of 88.21% and an average discharge voltage decay of 0.4019 V upon 150 cycling at 0.5 C. On the other side, Al&F co-doping can increase the electronic and ionic conductivity, and further enhance the rate property with a discharge capacity of 157 mAh g-1 at 10 C. In addition, the thermal stability was significantly meliorated by Al&F co-doping, which the initial exothermal peak was 273 ? and the overall heat generation was 221 J g-1.In order to mitigate the volume expansion of NiO anodes during charge-discharge process, homogeneous 1D hollow NiO anodes with excellent electrochemical performance were prepared via Ostwald Ripening Mechanism assisted with microemulsion. The NiO anode displayed an initial discharge capacity of 1086.2 mAh g-1 with a retention of 75.00% and a discharge capacity of 884.8 mAh g-1 after 100 cycles at 0.1 C. It also exhibited a discharge capacity of 492.5 mAh g-1 after 80 cycles at 5 C and an average discharge capacity as high as 363.0 mAh g-1 at 10C. Moreover, 1D hollow NiO anodes with superior electrochemical performance can be also obtained by using tenfold of the original reaction system or taking advantage of recycled oil phase,declaring that the 1D hollow NiO anodes could be scaled up and the oil phase could be reused to decline cost and pollution.