Influence of Mesoporosity on Lithium-Ion Storage Capacity and Rate Performance of Nanostructured TiO2(B)

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• 作者：Anthony G. Dylla ; Jonathan A. Lee ; Keith J. Stevenson
• 刊名：Langmuir
• 出版年：2012
• 出版时间：February 7, 2012
• 年：2012
• 卷：28
• 期：5
• 页码：2897-2903
• 全文大小：408K
• 年卷期：v.28,no.5(February 7, 2012)
• ISSN：1520-5827

文摘

Here, we present the Li⁺ insertion behavior of mesoporous ordered TiO₂(B) nanoparticles (meso-TiO₂(B)). Using presynthesized 4 nm TiO₂(B) nanoparticles as building blocks and a commercially available ethylene glycol-propylene glycol block copolymer (P123) as a structure-directing agent, we were able to produce mesoporous structures of high-purity TiO₂(B) with nanocrystallinity and mesopore channels ranging from 10 to 20 nm in diameter. We compared the Li⁺ insertion properties of nontemplated TiO₂(B) nanoparticles (nano-TiO₂(B)) to meso-TiO₂(B) via voltammetry and galvanostatic cycling and found significant increases in overall Li⁺ insertion capacity for the latter. While nano-TiO₂(B) and meso-TiO₂(B) both show surface charging (pseudocapacitive) Li⁺ insertion behavior, meso-TiO₂(B) exhibits a higher overall capacity especially at high charge rates. We attribute this effect to higher electrode/electrolyte contact area as well as the improved electron and ion transport in meso-TiO₂(B). In this study, we have demonstrated the influence of both nanostructuring and mesoporosity on Li⁺ insertion behavior by rationally controlling the overall architecture of the TiO₂(B) materials.