Ultrafast preparation of LiNi0.5Co0.2Mn0.3-xMgxO2 cathode materials by a facile microwave reaction

LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM) layered oxide is recognized as a promising cathode material of lithium ions battery and generally synthesized using a co-precipitation reaction to firstly obtain hydroxide precursors following by high-temperature solid method. The co-precipitation has the relatively complex and time-consuming process, whilst showing the nonuniform lithium distribution when mixed with spherical hydroxide precursors. Herein, a facile one-step microwave method is proposed to fast synthesize various LiNi 0.5 Co 0.2 Mn 0.3-x Mg x O 2 (x ≤ 0.05) cathode materials at a microwave power of 720 W only for 5 min. And then traditional solid method is used to further enhance the crystallinity and reduce the Li + /Ni 2+ mixing of the LiNi 0.5 Co 0.2 Mn 0.3-x Mg x O 2 samples. The as-prepared LiNi 0.5 Co 0.2 Mn 0.3-x Mg x O 2 samples have analogous polyhedral morphology and uniform element distribution. Also, the substitution of appropriate Mg-doping for Mn element boosts the stable layered structure and facilitates the Li + ions diffusion. Owing to these merits, the optimized LiNi 0.5 Co 0.2 Mn 0.27 Mg 0.03 O 2 cathode material exhibits a higher capacity retention of 87.90 % than that of the pristine LiNi 0.5 Co 0.2 Mn 0.3 O 2 sample (78.12 %) after 100 cycles at 0.2C.