基于yolk-shell泡泡纸复合结构的构筑及其在锂/钠离子电池中的应用

Exploring suitable alternative materials for carbon negative electrodes has been a hot research spot for lithium/sodium ion batteries. In the case of sodium ion batteries, exploring a negative electrode material with high capacity and excellent cycle performance is even a key bottleneck to realize the practical application of sodium ion batteries. Elemental metal or alloy anode materials with ultrahigh theoretical specific capacity and high rate capacity, are ideal choice of negative materials for development of high-performance lithium ion battery and developing practical sodium ion battery. However, these materiasl still meet some key problems, such as large volume expansion and poor cycle performance. The subject innovatively proposed yolk-shell bubble paper nanostructure, will prepare some metallic or alloy oxide (Si, Sn, Mo, Ge, Sb and alloy oxide) nanoparticles, and then coated them with carbon bubble paper. Finally, the oxides are reduced and synthsize elemental metal or alloy nanoparticles/void/carbon bubble paper composite structure. Such new composite structure can provide the space for the expansion of the metal or alloy nanoparticles to restrain the spalling and clustering of these nanoparticles, and the large-area coating layer of the carbon bubble paper also suppresses the pulverization of the electrode material. This design of such novel composite structure has important significance to realize lithium/sodium ion batteries with high capacity, high cycle performance, high rate performance and excellent low temperature performance.

探索合适的碳负极替代材料是锂/钠离子电池研究的热点。对钠离子电池而言，寻找具有高容量及循环性能优异的负极材料更是实现钠离子电池实用化的关键瓶颈。金属单质或者合金负极材料具有超高的理论比容量，可大电流放电，是研发高性能锂离子电池和开发实用化钠离子电池负极材料的理想选择。然而，目前仍然都面临体积膨胀大和循环性能差等关键问题。本课题创新性地提出了yolk-shell泡泡纸纳米复合结构，拟通过制备金属单质或者合金氧化物（Si，Sn，Mo，Ge，Sb及其合金氧化物）纳米颗粒，再用碳包覆成泡泡纸结构，最后经氧化物还原得到金属单质或者合金纳米颗粒/空腔/碳泡泡纸包覆的新型复合结构。这种分立的泡泡很好地提供了纳米颗粒体积膨胀所需的空间，抑制了纳米颗粒的剥落和颗粒团簇，大面积的泡泡纸同时也抑制了电极材料的粉化。这种复合结构设计对实现高容量、高循环性能、高倍率性能和优异低温性能的锂/钠离子电池具有重要意义。

探索合适的碳负极替代材料是锂/钠离子电池研究的热点。对钠离子电池而言，寻找具有高容量及循环性能优异的负极材料更是实现钠离子电池实用化的关键瓶颈。金属单质或者合金负极材料具有超高的理论比容量，可大电流放电，是研发高性能锂离子电池和开发实用化钠离子电池负极材料的理想选择。然而，目前仍然都面临体积膨胀大和循环性能差等关键问题。本课题创新性地提出了yolk-shell泡泡纸纳米复合结构，拟通过制备金属单质或者合金氧化物（Si，Sn，Mo，Ge，Sb及其合金氧化物）纳米颗粒，再用碳包覆成泡泡纸结构，最后经氧化物还原得到金属单质或者合金纳米颗粒/空腔/碳泡泡纸包覆的新型复合结构。这种分立的泡泡很好地提供了纳米颗粒体积膨胀所需的空间，抑制了纳米颗粒的剥落和颗粒团簇，大面积的泡泡纸同时也抑制了电极材料的粉化。制备了 Si，Sn，Mo，Ge，Sb 及其合金的Yolk-shell 泡泡纸复合材料。实现了锂/钠离子电池用金属合金Yolk-shell 泡泡纸负极材料比容量达到400 mAh g-1 以上，0.5C 充放电循环500 次保持率在80 %以上，5C 充放电的比容量达到0.1C 充放电比容量的80 %以上。通过本项目的支撑，共发表 SCI 论文18篇，授权发明专利5项。