Figure - available from: Journal of Materials Science: Materials in Electronics
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A LiNiO2 cathode material was cosubstituted with Mg and Al to obtain LiNi0.90Mg0.05Al0.05O2 via solid-state sintering of a mixture containing stoichiometric amounts of Ni(OH)2 precursor, LiOH·H2O, MgO, and Al2O3. The number of Li/Ni anti-site defects shown by X-ray diffraction was significantly reduced after cosubstitution of Mg and Al, and a 2–3 n...
Citations
... Specifically, Al element has a strong Al-O bond, which can inhibit phase transition, and Mg element can be inserted into the lithium layer, and act as a pillar to prevent the collapse of the layered structure under the high delithiation state. Recently, Al and Mg elements have been used in the modification of LNO in many studies [22,23]. However, although the capacity retention was significantly improved, conventional high-content Al and Mg doping resulted in an evident decrease in the reversible capacity and rate capability of LNO, which can somewhat offset the benefits of the capacity retention improvement achieved by doping [24,25]. ...
Owing to its high discharge capacity, which is close to the theoretical capacity, LiNiO2 (LNO) is considered an attractive cathode material for high-energy lithium-ion batteries. However, LNO secondary spherical cathode materials prepared by the conventional precipitation method have shown unsatisfactory cycle performance and a limited large-rate discharge capacity due to their extremely poor structure and interfacial stability. In this work, we reported on the surface reconstruction of LNO induced by the heterogeneous doping of Al and Mg via a segmented coprecipitation method and subsequent calcination. The modified LNO cathode (NAMg) showed decent cycle stability and a large-rate discharge ability (177.9 mA h g−1 at 10 C) against the Li anode in a voltage range of 2.8–4.35 V. The prototype full cell with a carbon anode had a superior cycling stability of 95.1% after 150 cycles. The loose and porous morphology increased the specific surface area and facilitated the rapid transport of Li+ ions. Moreover, the doping of Mg and Al alleviated harmful phase transition during the cycling process. This work demonstrates that the morphology, structure, and performance of LNO could be effectively adjusted by regulating the distribution of the doping elements, providing a new strategy for the synthesis of high-performance Ni-based cathode materials.
