Grain-boundary-rich mesoporous NiTiO3 micro-prism as high tap-density, super rate and long life anode for sodium and lithium ion batteries

Abstract

Titanium based compounds, such as TiO2, Li5Ti4O12 and Na2TinO2n+1 (where n = 3–8), have been pursued intensively for high energy and high power sodium and lithium ion batteries (NIBs and LIBs). Beside high rate and long life, the relatively higher capacity, higher tap density, scalable preparation process and low production cost are also essential factors for promising anode materials to progress from laboratory scale to pilot scale and finally to commercially scale up. Therefore, a dual-metal-organic crystal derived NiTiO3 mesoporous micro-prism is developed by a scalable and unique self-assembly process. The interesting assembling mechanism is also clearly discussed based on the colour and microstructure evolutions of the reaction solution at different stage. The obtained NiTiO3 hexagonal micro-prism features interconnected grain-boundary-rich and mesoporous structure, endowing highly conductive path for charge transportation and shortcut for ion diffusion. Together with a high tap density (2.5gcm−3), this anode materials can deliver a high capacity of 373 and 562mAhg−1 with superior rate and capacity retention for both sodium and lithium ion storage, respectively. It is also noteworthy that even after cycling for 1000 cycles at 5000mAg−1, the capacity retention ratio is maintained at 44.3% and 60.4% for sodium and lithium ion storage, respectively. The superior electrochemical properties, coupled with the low cost, dense structure and the scalable preparation method, will bring NiTiO3 micro-prism to the fore as a promising contender anode material for long durability and high power compact NIBs and LIBs.