Transformation of sludge Si to nano-Si/SiOx structure by oxygen inward diffusion as precursor for high performance anodes in lithium ion batteries

Abstract

Although several Si/C composite structures have been proposed for high-performance lithium-ion batteries (LIBs), they have still suffered from expensive and complex processes of nano-Si production. Herein, a simple, controllable oxygen inward diffusion was utilized to transform Si sludge obtained from the photovoltaic (PV) industry into the nano-Si/SiOx structure as a result of the high diffusion efficiency of O inside Si and high surface area of the sludge. After further process, a yolk/shell Si/C structure was obtained as an anode material for LIBs. This composite demonstrated an excellent cycling stability, with a high reversible capacity (∼ 1250 mAh/g for 500 cycles), by void space originally left by the SiOx accommodate inner Si expansion. We believe this is a rather simple way to convert the waste Si into a valuable nano-Si for LIB applications.

Metal–Organic Frameworks‐Derived Mesoporous Si/SiOx@NC Nanospheres as a Long‐Lifespan Anode Material for Lithium‐Ion Batteries

“…This general phenomenon has been widely observed in Si/SiO x ‐based anode materials in LIBs, where the capacity drops to a certain extent and then gradually increases. More detailed research into the electrochemical reaction process is still needed . The Si/SiO x @NC‐650 anode exhibits a large capacity of 586.6 mAh g −1 after 180 cycles, with a high coulombic efficiency of 99.2 % after 400 cycles.…”

Fabrication of a Sustainable Closed Loop for Waste-Derived Materials in Electrochemical Applications

“…The sludge was used to produce a nano-Si/SiOx structure as the precursor for high performance anodes in lithium-ion batteries. 83 The organic content also formed a porous support for metals. 84 Apart from metals and organics, some ISW contained some unnecessary components (such as ash content) for electrochemical applications.…”

“…A photovoltaic industry sludge contained both Si and organics. The sludge was used to produce a nano-Si/SiOx structure as the precursor for high performance anodes in lithium-ion batteries . The organic content also formed a porous support for metals .…”

Constructing a Sheet-Stacked Si/C Composite by Recycling Photovoltaic Si Waste for Li-Ion Batteries

“…Zhang et al 20 adopted surface modifications to enhance the conductive network between waste Si surface and the binder, and the reversible capacity of the modified Si electrode can retain 2638.5 mA h g −1 at the 200th cycle. Hua et al 21 transformed waste Si to the Si/SiO x structure to introduce the buffer matrix, which demonstrates a good cyclic stability, having a capacity of 1250 mA h g −1 at the 500th cycle. Chen et al 22 constructed a Si−P core shell structure where the P nanoshell would convert to Li 3 P during the initial lithiation process, providing high ionic conductivity and reducing the direct contact of the electrolyte to active Si.…”