Enhancing the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 cathodes through amorphous coatings

LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) cathodes have attracted the attention of the automotive industry due to their higher capacity and operating voltage. Despite their promising electrochemical behavior, these materials do not have a stable cycling performance, as parasitic reactions take place when they come in contact with the electrolyte. Herein, amorphous Nb 2 O 5 is applied as a multifunctional protective layer to stabilize the NCM811 interface, resulting in reduced surface contamination (Li 2 CO 3 ), alleviation of transition metal (TM) ion dissolution, and suppression of surface corrosion and phase transformations during cycling. As a result, after 200 cycles, the coated NCM811 had a capacity of 180 mAh g −1 displaying an excellent capacity retention of 85.7%, which is 30% higher than that of the uncoated samples. Similarly, the Nb 2 O 5 coating allows for an enhanced rate capacity of 139 mAh g −1 at 5 C, compared to 117.6 mAh g −1 for the pure NCM811. In addition, the Nb 2 O 5 coating effectively suppresses the voltage decay with cycling, resulting in a voltage decay of 70 mV after 200 cycles, while a reduction of 190 mV takes place without the coating.