Long-Lifespan Zinc-Ion Batteries Boosted by a Carbon Fiber Scaffold after Low-Temperature Plasma Treatment

With the rapid development of energy storage devices, aqueous zinc-ion batteries (ZIBs) have received great attention due to their high theoretical capacity, low cost, and high safety. However, the poor cycle life due to dendrites caused by uneven zinc stripping/plating restricts their commercial application. Herein, an artificial layer, carbon fiber (CF) scaffold treated by low-temperature plasma (LTP), which is placed between the zinc anode and the separator, is proposed to inhibit dendrites. In this work, the increased polar groups obtained from LTP treatment on the surface of CFs can act as nuclear sites and induce uniform deposition of zinc on the surface. Furthermore, the uniform electric field distribution and the smaller local current on CF surfaces can lead to a smaller and more homogeneous deposition. In addition, the CFs above the zinc anode can inhibit the excessive growth of dendrites on the zinc anode due to the suppressive effect. As a result, symmetric cells with the CF scaffold show a smaller polarization voltage and a longer cycling life of over 1000 h, and full cells based on the MnO2 cathode show better reversibility and rate performance. We believe that our research can bring potential ideas and inspiration in surface engineering strategies for dendrite-free Zn anodes and boost the development of advanced aqueous ZIBs.