Bimetal-organic-framework derived CoTiO₃ mesoporous micro-prisms anode for superior stable power sodium ion batteries

Abstract

Durability, rate capability, capacity and tap density are paramount performance metrics for promising anode materials, especially for sodium ion batteries. Herein, a carbon free mesoporous CoTiO3 micro-prism with a high tap density (1.8 g cm−3) is newly developed by using a novel Co-Ti-bimetal organic framework (BMOF) as precursor. It is also interesting to find that the Co-Ti-BMOF derived carbon-free mesoporous CoTiO3 micro-prisms deliver a superior stable and more powerful Na+ storage than other similar reported titania, titanate and their carbon composites. Its achieved capacity retention ratio for 2,000 cycles is up to 90.1% at 5 A g−1. 负极材料的循环、 倍率、 容量和堆积密度是评价钠离子电池性能的关键指标. 为此本工作开发了一种新型的钴-钛双金属-有机框架结构材料并以其作为前躯体衍生制备了具有1.8 g cm−3高堆积密度的无碳介孔钛酸钴微米棱柱状材料. 作为钠离子电池负极材料该种材料展示了超高稳定性同时拥有比其他类似的钛氧化物、 钛酸盐及其碳基复合材料更优异的倍率性能, 其在5 A g−1的电流密度下循环2000圈后容量保持率高达90.1%.