Zhou Yang, Pan Qiwen, Zhang Jing, Han Chunmiao, Wang Lei, Xu Hui
Key Laboratory of Functional Inorganic Material Chemistry Chinese Ministry of Education Heilongjiang University 74 Xuefu Road Harbin 150080 P. R. China.
Energy & Environmental Research Institute of Heilongjiang Province Heilongjiang Academy of Sciences Harbin 150090 P. R. China.
Adv Sci (Weinh). 2020 Dec 3;8(2):2002579. doi: 10.1002/advs.202002579. eCollection 2021 Jan.
Morphological control is a fundamental challenge of nanomaterial development. Commonly, hierarchical nanostructures cannot be induced by a single driving force, but obtained through balancing multiple driving forces. Here, a feasible strategy is reported based on the synergistic effect of proton and acid anion, leading to the morphological variation of vanadium oxide from nanowire, bundle, to hierarchical nanoflower (HNF). Protons can only induce the formation of nanowire through reducing the pH value ≤ 2. However, acid anions with strong coordination ability, e.g., phosphate radicals, can also participate in morphological regulation at high concentration. Through coordinating with exposed vanadium ions, the enrichment of phosphate radicals at ledge and kink changes the growth directions, giving rise to the advanced structures of bundle and HNF. The lithium ion batteries using HNF as a cathode achieve a 30% improved initial discharge specific capacity of 436.23 mAh g at a current density of 0.1 A g, reaching the theoretical maximum value of vanadium oxide based on insertion/desertion of three lithium ions, in addition to strong cyclic stability at 1 A g.
形态控制是纳米材料开发的一项基本挑战。通常，分级纳米结构不能由单一驱动力诱导形成，而是通过平衡多种驱动力来获得。在此，报道了一种基于质子和酸根阴离子协同效应的可行策略，该策略导致氧化钒的形态从纳米线、束状转变为分级纳米花（HNF）。质子只能通过将pH值降低至≤2来诱导纳米线的形成。然而，具有强配位能力的酸根阴离子，例如磷酸根，在高浓度时也能参与形态调控。通过与暴露的钒离子配位，磷酸根在台阶和扭结处的富集改变了生长方向，从而产生了束状和分级纳米花等高级结构。以分级纳米花作为阴极的锂离子电池，在电流密度为0.1 A g时，初始放电比容量提高了30%，达到436.23 mAh g，基于三个锂离子的嵌入/脱嵌达到了氧化钒的理论最大值，此外在1 A g时具有很强的循环稳定性。
