Cycling strategies for optimizing silicon nanowires performance as negative electrode for lithium battery

• Original cycling conditions combining cut-off potential and involved capacity
• Influence of capacity limitation is investigated for lithiation and delithiation
• Importance of a reduced delithiation cut-off voltage is demonstrated
• At C/5 rate, 1800 cycles are reached without electrode or electrolyte optimization
• A 1 C rate, 2000 cycles are reached with electrolyte containing VC additive

The cycling conditions of silicon nanowires anode are investigated and a set of conditions is proposed in order to improve the cycle life of these electrodes, without any structure or surface optimization. Limitation of lithiation or delithiation to an intermediate value of 900 mAh g−1 allows to perform up to 1850 cycles at C/5 rate, which represents a significant increase of the electrode cycle life compared to that observed for standard cycling. This behavior is still attractive at higher current rate. At 1 C rate, it is proved that combining the lithiation-limited cycling with an upper cut-off voltage of 0.8 V improves the capacity retention by a factor 2. When using these optimized conditions, combined with a simple adding of fluoroethylene carbonate or vinylene carbonate in the electrolyte, a compact solid electrolyte interphase is formed upon cycling and an exceptional capacity retention is observed, reaching respectively 1500 and more than 2000 cycles.