Department of Materials Science and Engineering, ‡Department of Mechanical Engineering, and §Materials Characterization Facility, Texas A&M University , College Station, Texas 77843, United States.
ACS Appl Mater Interfaces. 2017 Aug 30;9(34):28695-28703. doi: 10.1021/acsami.7b10158. Epub 2017 Aug 21.
The electrochemical performance of anodes made of transition metal oxides (TMOs) in lithium-ion batteries (LIBs) often suffers from their chemical and mechanical instability. In this research, a novel electrode with a hierarchical current collector for TMO active materials is successfully fabricated. It consists of porous nickel as current collector on a copper substrate. The copper has vertically aligned microchannels. Anatase titanium dioxide (TiO) nanoparticles of ∼100 nm are directly synthesized and cast on the porous Ni using a one-step process. Characterization indicates that this electrode exhibits excellent performance in terms of capacity, reliable rate, and long cyclic stability. The maximum insertion coefficient for the reaction product of LiTiO is ∼0.85, a desirable value as an anode of LIBs. Cross-sectional SEM and EDS analysis confirmed the uniform and stable distribution of nanosized TiO nanoparticles inside the Ni microchannels during cycling. This is due to the synergistic effect of nano-TiO and the hierarchical Cu/Ni current collector. The advantages of the Cu/Ni/TiO anode include enhanced activity of electrochemical reactions, shortened lithium ion diffusion pathways, ultrahigh specific surface area, effective accommodation of volume changes of TiO nanoparticles, and optimized routes for electrons transport.
锂离子电池（LIBs）中过渡金属氧化物（TMO）阳极的电化学性能往往受到其化学和机械不稳定性的影响。在这项研究中，成功制备了一种具有分层集流器的 TMO 活性材料新型电极。它由多孔镍作为铜基板上的集流器组成。铜具有垂直对齐的微通道。使用一步法直接在多孔 Ni 上合成和浇铸约 100nm 的锐钛矿二氧化钛（TiO）纳米粒子。表征表明，该电极在容量、可靠的倍率和长循环稳定性方面表现出优异的性能。LiTiO 反应产物的最大插入系数约为 0.85，是 LIBs 阳极的理想值。横截面 SEM 和 EDS 分析证实，在循环过程中纳米 TiO 纳米粒子在 Ni 微通道内均匀且稳定地分布。这归因于纳米-TiO 和分层 Cu/Ni 集流器的协同效应。Cu/Ni/TiO 阳极的优点包括增强电化学反应活性、缩短锂离子扩散途径、超高比表面积、有效容纳 TiO 纳米粒子的体积变化以及优化电子传输途径。
