Synthesis And Electrochemical Properties Of Nickel-Based Cathode Materials For Lithium-Ion Batteries

The preparation of Nickel-based cathode materials for Lithium-ion batteries was studied. Totally, two kinds of Nickel-based materials were synthesized. There were: 1. LiNi_0.8Co_0.2O₂, with α-NaFeO₂ structure, from Ni-Co hydroxy-carbonate precursor; 2. LiMn_0.4Ni_<sub>0.4Co_0.2O₂, from Mn-Ni-Co-Layered Double Hydroxide (Mn-Ni-Co-LDHs) precursor. Additional, mesoporous nanocrystal Co₃O₄ was also synthesized by thermal treatment of the Cobalt-hydroxy-carbonate precursor which obtained through the method involving separate nucleation and growth steps. In this thesis, many methods, such as XRD, ICP, FT-IR, TG/DTA-EGMS, TEM, SEM, FESEM and electrochemical testing, were employed to study reaction conditions and mechanisms. The relationships among structure, composition and electrochemical properties of materials were studied. The factors which affect the electrochemical properties of materials were investigated.The precursor, Ni-Co hydroxy-carbonate, was prepared by colloid mill method with NH₄HCO₃ as precipitator. And LiNi_<sub>0.8Co_0.2O₂ was obtained by mixed and calcinated with LiNO₃ as lithiating agent. There were three advantages of this preparation method. Firstly, NH4HCO3 was chosen as precipitator purity without interfusion of Na⁺ and K⁺ which have bad effect on the electrochemical properties of LiNi_0.8Co_0.2O₂. Secondly, easily...