To increase the energy storage density of lithium-ion batteries, silicon anodes have been explored due to their high capacity. One of the main challenges for silicon anodes are large volume variations during the lithiation processes. Recently, several high-performance schemes have been demonstrated with increased life cycles utilizing nanomaterials such as nanoparticles, nanowires, and thin films. However, a method that allows the large-scale production of silicon anodes remains to be demonstrated. Herein, we address this question by suggesting new scalable nanomaterial-based anodes. Si nanoparticles were grown on nanographite flakes by aerogel fabrication route from Si powder and nanographite mixture using polyvinyl alcohol (PVA). This silicon-nanographite aerogel electrode has stable specific capacity even at high current rates and exhibit good cyclic stability. The specific capacity is 455 mAh g−1 for 200th cycles with a coulombic efficiency of 97% at a current density 100 mA g−1.
Silicon anodes are
considered as promising electrode materials
for next-generation high capacity lithium-ion batteries (LIBs). However,
the capacity fading due to the large volume changes (∼300%)
of silicon particles during the charge–discharge cycles is
still a bottleneck. The volume changes of silicon lead to a fracture
of the silicon particles, resulting in recurrent formation of a solid
electrolyte interface (SEI) layer, leading to poor capacity retention
and short cycle life. Nanometer-scaled silicon particles are the favorable
anode material to reduce some of the problems related to the volume
changes, but problems related to SEI layer formation still need to
be addressed. Herein, we address these issues by developing a composite
anode material comprising silicon nanoparticles and nanographite.
The method developed is simple, cost-efficient, and based on an aerogel
process. The electrodes produced by this aerogel fabrication route
formed a stable SEI layer and showed high specific capacity and improved
cyclability even at high current rates. The capacity retentions were
92 and 72% of the initial specific capacity at the 171st and the 500th
cycle, respectively.
NiMn2O4 (NMO) is a good alternative anode material for lithium-ion battery (LIB) application, due to its superior electrochemical activity. Current research shows that synthesis of NMO via citric acid-based combustion method envisaged application in the LIB, due to its good reversibility and rate performance. Phase purity and crystallinity of the material is controlled by calcination at different temperatures, and its structural properties are investigated by X-ray diffraction (XRD). Composition and oxidation state of NMO are further investigated by X-ray photoelectron spectroscopy (XPS). For LIB application, lithiation delithiation potential and phase transformation of NMO are studied by cyclic voltammetry curve. As an anode material, initially, the average discharge capacity delivered by NMO is 983 mA·h/g at 0.1 A/g. In addition, the NMO electrode delivers an average discharge capacity of 223 mA·h/g after cell cycled at various current densities up to 10 A/g. These results show the potential applications of NMO electrodes for LIBs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.