الفهرس 
CHAPTER 1: IntroductionOnly 14 pages are availabe for public view
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Abstract
At present, lithium-ion batteries (LIBs) have been widely used in the field of new
electric vehicles. The energy density of such a battery system for new electric energy
vehicle is required to be high enough for meeting the requirement of vehicle mileage.
In this regard, the cathode active materials of LIBs are crucial for the electrochemical
performance, including capacity, energy density, and cycle life.
In this thesis, facile coprecipitation method is used to coat LiNi0.8Mn0.1Co0.1O2
(NMC811) cathode material by spinel ZnAl2O4 (ZAO) nanoparticles layer and
perovskite-type ZnSnO3 (ZTO) film for Lithium-ion batteries (LIBs). For
physicochemical characterization, the effects of different contents of ZAO and ZTO
coating layers on NCM811 particle surface on the morphologies, structures, and
compositions of the prepared cathode materials are systematically studied using XRD,
SEM, EDX, TEM, FTIR, and Raman spectroscopy. Coin cells (CR 2032) are assembled
with such coated NMC811 cathode materials for performance evaluation.
Electrochemical tests showed that the ZAO and ZTO coatings can stabilize the
NMC811 active materials resulting in a good performance of rechargeable LIBs. The
0.25% ZnAl2O4 coated sample delivers high capacity retention " ~ "82% than that of
pristine NMC811 " ~ " 60.2% after 100 cycles upon 1 C. The reduction in the separation
potentials of both anodic and cathodic CV scans gives a strong indication for enhancing
the structure stability and lowering the polarization between NMC811 particles. The
cathode sample 1% ZTO@NMC811 showed higher rate capability performance than
pristine NMC811, maintaining about 73% of its initial capacity even after re-cycling at
0.1C between cycle no. 25 and 30 and The enhanced electronic and ionic conduction
after ZnSnO3 film coating was certified by the significant decrease in Ohmic (Rs) and
charge transfer (Rct) resistances before and after cycling.