Electrochemical characteristics and energy densities of lithium-ion batteries using mesoporous silicon and graphite as anodes

Abstract

In order to fabricate high-energy and stable lithium-ion batteries (LIB), herein, mesoporous silicon (mpSi-Y) microparticles were prepared via a facile magnesiothermic reduction of commercial zeolite Y. The electrochemical characteristics of carbon-coated mpSi-Y (mpSi-Y/C) were evaluated in a lithium-ion battery full cell as well as a half-cell configuration and compared with those of silicon nanoparticle-carbon composite (SiNP/C) and graphite (Gr) anodes. With the mesoporous structural features of mpSi-Y, the high-capacity mpSi-Y/C (1200 mAh.g − 1 at 0.05 C) in a half-cell showed a much better cycling stability at a much less impedance build-up and electrode thickness increase than SiNP/C composite. It also presented much faster charging/discharging kinetics than does the graphite anode. A pretreated mpSi-Y/C was paired with a NCM (LiNi0.6Co0.2Mn0.2O2) cathode to fabricate a full cell, mpSi∥NCM. The mpSi∥NCM cell exhibited a comparable cycling performance to that of the Gr∥NCM cell at 0.5 C for 200 cycles. More importantly, detail analysis revealed that the size of the mpSi∥NCM cell can be smaller than that of the Gr∥NCM by more than 50%. The gain in specific energy density of the mpSi∥NCM cell over the Gr∥NCM was about 33%. Thus, the mpSi-Y/C can be promising anodes for stable and high-energy lithium-based batteries.