Se-Induced Fibrous Nano Red P with Superior Conductivity for Sodium Batteries

摘要

Red phosphorus shows great promise as a high-capacity anode materialfor Na batteries. Such electrodes that suffered from the fracturing impactof volume change during cycling can be effectively improved by 1D nanomaterials.However, the synthesis of 1D red phosphorus has rarely beenstudied and employed in sodium batteries. Here, a simple selenium-inducedmethod to generate fibrous nano red phosphorus is presented. It turns outthat a small amount of selenium can not only induce high-quality fibrousnano red phosphorus from commercial red phosphorus, but also benefitqualitatively to the sodium ionic conductivity. Interestingly, the seleniumdopant can also manipulate the chemical state of phosphorus leading tovalence tunability which is able to tolerate structural stability under theNa-rich or Na-poor condition. As a result, the optimal fibrous nano red phosphorusused as anode outperforms over the traditional red phosphorus ≈6and ≈10 times in terms of rate performance and cycle stability, respectively.Furthermore, as employed for sodium metal anode protection, the symmetricalcell cycling maintains long stable at a low polarization voltage for over1000 h. The full cell performs excellent cycling stability of 1500 cycles at 3 Cand high-rate performance up to 30 C.