Hydrothermal synthesis of Co-free NMA cathodes for high performance Li-ion batteries.

Scalable and sustainable production of high voltage cathodes is required to meet the increasing demands for Li-ion batteries. Additionally, the anticipated scarcity of critical materials like cobalt necessitates demonstration of Co-free alternatives that can match the performance metrics of conventional cathodes. Herein, a hydrothermal synthesis route for production of a new class of high-capacity, cobalt-free cathode material, LiNi 0.9 Mn 0.05 Al 0.05 O 2 (NMA9055) for next-generation Li-ion batteries is reported. The synthesized cathode material shows high crystallinity and purity with monodispersed spherical morphology. Extensive electrochemical, structural, and post-mortem characterization of this novel NMA material is carried out. NMA-Li half cells show an initial discharge capacity of 200 mAh/g with a 96% capacity retention over 100 cycles when cycled between 3.0 and 4.4 V. On the other hand, NMA full cells with Li 4 Ti 5 O 12 (LTO) electrodes as the anode, show an initial discharge capacity of 186 mAh/g with 81% capacity retention over 200 cycles. Post-mortem structural and morphological characterization show that the NMA morphology and crystal structure do not degrade significantly over 200 charge/discharge cycles. This new class of cobalt free cathode material containing nickel, manganese and aluminum synthesized by an ammonia-free synthesis route is expected to provide a facile solution towards sustainable cathode production. • Hydrothermal method to synthesize LiNi 0.9 Mn 0.05 Al 0.05 O 2 (NMA) cobalt-free cathode. • High crystallinity and spherical morphology achieved by ammonia-free process. • NMA half cells show 200 mAh g−1 capacity with 96% capacity over 100 cycles. • NMA-LTO full cells shows capacity of 186 mAh g−1 with 81% retention over 200 cycles. • Extensive in-situ and ex-situ characterization performed to study the material. [ABSTRACT FROM AUTHOR]