Enhanced electrochemical performance and storage property of LiNi0.815Co0.15Al0.035O2 via Al gradient doping

LiNi1−x−yCoxAlyO2 is a commonly used Ni-rich cathode material because of its relatively low cost, excellent rate capability and high gravimetric energy density. Surface modification is an efficient way to overcome the shortcomings of Ni-rich cathodes such as poor cycling stability and poor thermal stability. A high-powered concentration-gradient cathode material with an average composition of LiNi0.815Co0.15Al0.035O2 (LGNCAO) has been successfully synthesized by using spherical concentration-gradient Ni0.815Co0.15Al0.035(OH)2 (GNCA)as the starting material. An efficient design of the Al3+ precipitation method is developed, which enables obtaining spherical GNCA with ∼10 μm particle size and high tap density. In LGNCAO, the nickel and cobalt concentration decreases gradually whereas the aluminum concentration increases from the centre to the outer layer of each particle. Electrochemical performance and storage properties of LGNCAO have been investigated comparatively. The LGNCAO displays better electrochemical performance and improved storage stability than LNCAO.