Abstract
NCA (LiNi0.85Co0.10Al0.05-x MxO2, M=Mn or Ti, x < 0.01) cathode materials are prepared by a hydrothermal reaction at 170°C and doped with Mn and Ti to improve their electrochemical properties. The crystalline phases and morphologies of various NCA cathode materials are characterized by XRD, FE-SEM, and particle size distribution analysis. The CV, EIS, and galvanostatic charge/discharge test are employed to determine the electrochemical properties of the cathode materials. Mn and Ti doping resulted in cell volume expansion. This larger volume also improved the electrochemical properties of the cathode materials because Mn4+ and Ti4+ were introduced into the octahedral lattice space occupied by the Li-ions to expand the Li layer spacing and, thereby, improved the lithium diffusion kinetics. As a result, the NCA-Ti electrode exhibited superior performance with a high discharge capacity of 179.6 mAh g−1 after the first cycle, almost 23 mAh g−1 higher than that obtained with the undoped NCA electrode, and 166.7 mAh g−1 after 30 cycles. A good coulombic efficiency of 88.6% for the NCA-Ti electrode is observed based on calculations in the first charge and discharge capacities. In addition, the NCA-Ti cathode material exhibited the best cycling stability of 93% up to 30 cycles.
Highlights
There is an increasing consumer demand for Liion batteries (LIBs) with long life, high energy, and high power density
Several limitations such as a difficult synthesis protocol for stoichiometric LiNiO2, partially reversible phase for LiNiO2, and Li/Ni cation mixing have to be overcome before LiNiO2 can be commercially used as a cathode material for LIBs
The NCA cathode materials were prepared via one step of hydrothermal reaction
Summary
There is an increasing consumer demand for Liion batteries (LIBs) with long life, high energy, and high power density. Transition metal-layered oxide LiMO2 (M=Ni, Mn, Co) materials have generated interest as suitable solutions to the aforementioned issues, including specific capacity, energy density, safety, and cost [3, 4]. Among these materials, LiNiO2 is of low cost, has a large theoretical capacity (275 mAh g−1), and is more environmentally friendly than LiCoO2 [5,6,7,8]. Co and Al codoped LiNi1−x−yCoxAlyO2 (NCA, 0.05 ≤ x ≤ 0.15, 0.01 ≤ y ≤ 0.10) cathode materials exhibit the improved electrochemical properties and the thermal safety because cation substitution of Co and Al increases the stability of the structure [5, 9].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
