However, in practice, they have proven expensive to implement. To address problems arising from the large volumetric expansion of Si, various approaches to develop nano-structured Si have been proposed. As such, few Si-based electrodes are currently comprised entirely of Si, but are usually combinations of graphite and small amounts of Si 7, 8, 9, 10, 11. Since these issues are associated with the loss of active material (Si), low Coulombic efficiency, and loss of contact for ionic and electrical conduction, they ultimately result in the rapid decay of cell capacity. These changes in volume not only tend to pulverize silicon particles, and lead to the repeated loss and formation of the solid electrolyte interphase (SEI) layer, but also cause detachment from the current collector and structural collapse between electrodes. 400%) volumetric expansion/shrinking during repeated charge/discharge processes, which causes Si-based LIBs (cells) to have generally poor cycle lives. Silicon is also highly cost-effective being one of the most abundant elements on earth 1, 2, 3, 4, 5, 6.ĭespite the aforementioned advantages, however, silicon exhibits huge (ca.
In addition to its high capacity, silicon is an effective material for anodes because of its low discharge voltage, and is suited for batteries with high energy density.
For such applications, silicon (4,200 mAh g −1, Li 4.4Si), which has a significantly higher theoretical capacity than commercialized graphite (372 mAh g −1, LiC 6), is recognized to be a promising anode material.
High-capacity battery materials are in high demand for use in lithium-ion batteries (LIBs) in Electric Vehicles (EVs) and Energy Storage Systems (ESS), which have high energy density requirements.
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