Silicon Nanoparticles Coated with Chitosan for Using Anode of a Lithium Secondary Ion Battery

Si has advantages such as high battery capacity, low discharge potential (below 0.5 V), and low cost by acting with lithium ion that can be represented as the following equation, but it is known to have lots of problems such... [ view full abstract ]

Si has advantages such as high battery capacity, low discharge potential (below 0.5 V), and low cost by acting with lithium ion that can be represented as the following equation, but it is known to have lots of problems such as a capacity fading problem due to pulverization, low electrical contact, and large volumetric change according to solid electrolyte interphase (SEI) generation. This expansion is known to be carried out up to about 400 %. New materials such as Si-C and Si-Polymer are being actively progressed. If a metal such as Si is used as anode active material, lithium moves into the metal and takes up a gap between metals and reacts so that volume expansion occurs due to increased lattice constant.
In this study, the Si-chitosan (CTS) was prepared by introduced from 3 molecular chitosan (low, medium, high) to Si nanoparticles. From these, the difference in battery efficiency was investigated when making lithium secondary battery half cell through the carbonization of Si based material by using low, medium and high molecular chitosan polymers.
For the assessment of the physical properties of synthesized Si-CTS composite, FT-IR, TEM, SEM, XPS and elemental analyzer were employed for the characterization of physicochemical properties. The characteristics of the carbonized silicon anode active materials synthesized by using each method were electrochemically evaluated.