Huge volume expansion, unstable SEI-film evolution and uncontrollable Li plating remain challenging issues for achieving high energy-density and fast charging graphite/silicon anodes. Unfortunately, less reports on Li plating in graphite/silicon anodes have been found up to now. Herein, for the first time, we report that the interfacial polarization of silicon dominates the co-lithiation process with graphite, thus determining the preferential Li-plating sites and SEI film evolution. Interestingly, the disturbance of local electrochemical potential due to consecutive volume variation of silicon upon cycling, indeed keep Li plating sites changing and deteriorate the battery performances. In a typical case of silicon, global electrochemical potential-equilibrium of electrons in silicon can be achieved by regulating Li-ion diffusion kinetic in silicon, thus delaying Li-plating on graphite. Comparing to commercial silicon, P-type photovoltaic silicon exhibits weaker disturbance of local electrochemical potential upon volume variation, resulting in smaller change in Li-plating sites and smaller re-growth SEI film. Therefore, our findings propose a new perspective on the competitive lithiation mechanism and Li plating for graphite/silicon anodes which is highly desirable for designing high-capacity and fast-charging graphite/silicon.

巨大的体积膨胀、不稳定的 SEI 膜演化和不可控的锂电镀仍然是实现高能量密度和快速充电石墨/硅负极的挑战性问题。遗憾的是，迄今为止，关于石墨/硅负极镀锂的报道较少。在此，我们首次报道了硅的界面极化在与石墨的共锂化过程中起主导作用，从而决定了优先的镀锂位点和 SEI 膜的演化。有趣的是，由于硅在循环过程中的连续体积变化而引起的局部电化学势的干扰，确实使锂电镀位点发生变化并降低了电池性能。在硅的典型情况下，通过调节硅中的锂离子扩散动力学，可以实现硅中电子的全局电化学势平衡，从而延迟石墨上的锂电镀。与商业硅相比，P型光伏硅在体积变化时表现出更弱的局部电化学势扰动，导致镀锂位点的变化更小，再生长的SEI膜也更小。因此，我们的研究结果为石墨/硅负极的竞争性锂化机制和镀锂提出了新的视角，这对于设计高容量和快速充电的石墨/硅非常有用。导致镀锂位点的变化更小，SEI 膜的再生长更小。因此，我们的研究结果为石墨/硅负极的竞争性锂化机制和镀锂提出了新的视角，这对于设计高容量和快速充电的石墨/硅非常有用。导致镀锂位点的变化更小，SEI 膜的再生长更小。因此，我们的研究结果为石墨/硅负极的竞争性锂化机制和镀锂提出了新的视角，这对于设计高容量和快速充电的石墨/硅非常有用。