A Nanopile Interlocking Separator Coating towards Uniform Li Deposition of the Li Metal Anodes.
A Nanopile Interlocking Separator Coating towards Uniform Li Deposition of the Li Metal Anodes.
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DOI：
10.1021/acsami.0c08776
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发表时间：
2020-09
影响因子：
9.5
通讯作者：
Honglei Yue;Qiaonan Zhu;Shuai Dong;Yan Zhou;Yan Yang;Liwei Cheng;Mengmeng Qian;Lei Liang;Wei Wei-Wei;Hua Wang
中科院分区：
文献类型：
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作者：
Honglei Yue;Qiaonan Zhu;Shuai Dong;Yan Zhou;Yan Yang;Liwei Cheng;Mengmeng Qian;Lei Liang;Wei Wei-Wei;Hua Wang
锂(Li)枝晶的生长失控严重阻碍了锂金属阳极的发展，而隔板改造被认为是抑制Li枝晶生长的一种简单有效的方法。然而，由于聚烯烃隔膜的杨氏模数不同，导致涂层脱落的“落渣”现象会导致锂离子通量不均匀，最终导致电池的电化学性能恶化，甚至热失控。在这里，我们引入了一种新的纳米级机械联锁策略来创建无分层的隔膜修饰，该策略可以稳定地产生均匀的Li离子通量，以指导长期均匀的Li沉积。实验和模拟结果都表明，基于这种物理互锁机理，涂层与膜基质之间具有很强的结合强度。因此，几乎没有枝晶的Li沉积和大大降低的界面阻抗，成功地实现了加入这种改进的隔膜的Li//Li半电池1000h的稳定循环。而Li/LiFePO4全电池的长期循环稳定性显著提高到500次，进一步显示了其良好的实用潜力。此外，这种方法不需要任何粘结剂或表面活化过程，可以很容易地放大，为稳定的锂金属阳极提供一种适用和持久的隔膜改性解决方案。
Uncontrollable growth of Lithium (Li) dendrite has severely hindered the development of Li metal anodes, while separator modification is regarded as a simple and effective way to mitigate the growth of Li dendrite. However, the "drop-dregs" phenomenon of coating layer desquamated from polyolefin separator due to their different Young's modulus would induce non-uniform Li ionic flux, finally resulting in deteriorative electrochemical performance and even thermal runaway of the battery. Herein, we introduce a novel nanopile mechanical interlocking strategy to create delamination-free separator modification, that could stably generate homogeneous Li ionic flux to guide long-term uniform Li deposition. Both experimental and simulation results demonstrate strong bonding strength between coating layer and membrane matrix based on this physical interlocking mechanism. Consequently, with nearly dendrite-free Li deposition and largely reduced interface impedance, 1000 h stable cycling of Li//Li half cells enrolled this modified separator is successfully achieved. And a significantly improvement of Li/LiFePO4 full cells in long-term cycling stability to 500 cycles further indicates its promising practical potential. Moreover, this presented approach without any binding agents or surface activation procedures could be facilely scaled up, providing an applicable and durable separator modification solution towards stable Li metal anodes.