Kim Dongheun, Ahmed Towfiq, Crossley Kenneth, Baldwin J Kevin, Ra Shin Sun Hae, Kim Yeonhoo, Sheehan Chris, Li Nan, Pete Doug V, Han Henry H, Yoo Jinkyoung
Center for Integrated Nanotechnologies, Los Alamos National Laboratory Los Alamos NM 87545 USA
T-4, Los Alamos National Laboratory Los Alamos NM 87545 USA.
Nanoscale Adv. 2022 Mar 9;4(8):1962-1969. doi: 10.1039/d1na00844g. eCollection 2022 Apr 12.
Uniform size of Si nanowires (NWs) is highly desirable to enhance the performance of Si NW-based lithium-ion batteries. To achieve a narrow size distribution of Si NWs, the formation of bulk-like Si structures such as islands and chunks needs to be inhibited during nucleation and growth of Si NWs. We developed a simple approach to control the nucleation of Si NWs interfacial energy tuning between metal catalysts and substrates by introducing a conductive diffusion barrier. Owing to the high interfacial energy between Au and TiN, agglomeration of Au nanoparticle catalysts was restrained on a TiN layer which induced the formation of small Au nanoparticle catalysts on TiN-coated substrates. The resulting Au catalysts led to the nucleation and growth of Si NWs on the TiN layer with higher number density and direct integration of the Si NWs onto current collectors without the formation of bulk-like Si structures. The lithium-ion battery anodes based on Si NWs grown on TiN-coated current collectors showed improved specific gravimetric capacities (>30%) for various charging rates and enhanced capacity retention up to 500 cycles of charging-discharging.
硅纳米线（NWs）的均匀尺寸对于提高基于硅纳米线的锂离子电池的性能非常重要。为了实现硅纳米线窄尺寸分布，在硅纳米线的成核和生长过程中需要抑制块状硅结构（如岛状和块状）的形成。我们开发了一种简单的方法来控制硅纳米线的成核，即通过引入导电扩散阻挡层来调节金属催化剂与衬底之间的界面能。由于金与氮化钛之间的界面能较高，金纳米颗粒催化剂的团聚在氮化钛层上受到抑制，这导致在涂有氮化钛的衬底上形成小的金纳米颗粒催化剂。由此产生的金催化剂导致硅纳米线在氮化钛层上成核和生长，具有更高的数密度，并且硅纳米线直接集成到集流体上，而不会形成块状硅结构。基于在涂有氮化钛的集流体上生长的硅纳米线的锂离子电池阳极，在各种充电速率下均表现出提高的比容量（>30%），并且在高达500次充放电循环中容量保持率提高。
