Piranha Solution-Assisted Surface Engineering Enables Silicon Nanocrystals with Superior Wettability and Lithium Storage
Tingting Li,
Yangfan Li,
Fan Zhang,
Naiwen Liang,
Jiang Yin,
Haihong Zhao,
Yahui Yang,
Bo Chen,
Lishan Yang
Affiliations
Tingting Li
National and Local Joint Engineering Laboratory for New Petrochemical Materials and Fine Utilization of Resources, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, Hunan Normal University, Changsha 410081, China
Yangfan Li
National and Local Joint Engineering Laboratory for New Petrochemical Materials and Fine Utilization of Resources, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, Hunan Normal University, Changsha 410081, China
Fan Zhang
National and Local Joint Engineering Laboratory for New Petrochemical Materials and Fine Utilization of Resources, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, Hunan Normal University, Changsha 410081, China
Naiwen Liang
National and Local Joint Engineering Laboratory for New Petrochemical Materials and Fine Utilization of Resources, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, Hunan Normal University, Changsha 410081, China
Jiang Yin
National and Local Joint Engineering Laboratory for New Petrochemical Materials and Fine Utilization of Resources, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, Hunan Normal University, Changsha 410081, China
Haihong Zhao
National and Local Joint Engineering Laboratory for New Petrochemical Materials and Fine Utilization of Resources, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, Hunan Normal University, Changsha 410081, China
Yahui Yang
National and Local Joint Engineering Laboratory for New Petrochemical Materials and Fine Utilization of Resources, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, Hunan Normal University, Changsha 410081, China
Bo Chen
State Key Laboratory of Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM), School of Chemistry and Life Sciences, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
Lishan Yang
National and Local Joint Engineering Laboratory for New Petrochemical Materials and Fine Utilization of Resources, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, Hunan Normal University, Changsha 410081, China
Silicon anodes with a high theoretical capacity possess great potential applications in power batteries for electric vehicles, while their volume expansion always leads to crystal pulverization and electrode polarization. An ideal solution to alleviate such pulverization and polarization of silicon crystals is to simultaneously use nano-sized silicon crystals and introduce high viscosity and elasticity polymer binders. This work has achieved the adjustable introduction of hydroxyl groups to silicon nanocrystals under the optimal reaction temperature (e.g., 80 °C) and appropriate piranha solution composition (e.g., H2SO4/H2O2 = 3:1 v/v), ultimately forming an amorphous coating layer of ~1.3 nm on the silicon surface. The optimized silicon anode exhibits superior electrochemical performance (with an initial Coulombic efficiency of 85.5%; 1121.4 mA h g−1 at 1 A g−1 after 200 cycles) and improved hydrophilicity. The introduced hydroxyl groups significantly enhance the hydrophilicity of silicon in the electrolyte and the electrochemical activity of the silicon anodes. The hydroxyl groups achieve stronger bonding between silicon and polymer binders, ultimately improving the mechanical strength and stability of the electrode. The introduction of hydrophily functional groups on the surface of silicon crystals can be explored as an active strategy to solve the above issues. This surface engineering method could be extended to more fields of infiltrating silicon-based functional materials.
