Utilization of pelagic clay to prepare porous silicon as negative electrode for lithium-ion batteries

Abstract

In order to rationally develop abundant marine clay resources, in view of its large specific surface area, looseness, high porosity, poor crystallinity, and high activity, the magnesium thermal reduction method was used to reduce Si4+ in the pelagic clay minerals to obtain porous silicon. Through targeted process design and reaction condition control, the obtained silicon material not only has higher crystallinity, but also has layered accumulation pores with relatively uniform pore size distribution. It had a BET specific surface area of 81.473 m2·g−1, a pore volume of 0.290 cm3·g−1, and an average pore size of 10.193 nm. In addition, using sucrose as the carbon source, the prepared silicon was modified to obtain a carbon-coated porous silicon material, whose performance as lithium-ion battery negative electrode was preliminarily characterized. The specific capacity, cycling performance and multiplicity performance test results showed that the porous silicon derived from pelagic clay exhibits good cycling and rate performance under the carbon coating conditions, which means that it had a certain potential in the field of lithium-ion batteries. This work opened up a new way for high value-added utilization of pelagic clay.