Mid Sweden University

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 the 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 nano graphite. 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.

This study investigates the performance of silicon nanoparticles (Si NPs) and silicon nanographite (SiNG) composite-based anodes for lithium-ion batteries (LiBs). Si offers a promising alternative to traditional graphite anodes due to its higher theoretical capacity, despite encountering challenges such as volume expansion, pulverization, and the formation of a solid electrolyte interface (SEI) during lithiation. SiNPs anode exhibited initial specific capacities of 1568.9 mAh/g, decreasing to 1137.6 mAh/g after 100th cycles, with stable Li–Si alloy phases and high Coulombic efficiency (100.48%). It also showed good rate capability, retaining 1191.3 mAh/g at 8400 mA g−1 (2.82C), attributed to its carbon matrix structure. EIS indicated charge transfer with RB of 3.9 Ω/cm−2 and RCT of 11.4 Ω/cm−2. Contrastingly, SiNG composite anode had an initial capacity of 1780.7 mAh/g, decreasing to 1297.5 mAh/g after 100 cycles. Its composite structure provided cycling stability, with relatively stable capacities after 50 cycles. It exhibited good rate capability (1191.3 mAh/g at 8399.9 mA g−1), attributed to its carbon matrix structure. Electrochemical impedance spectroscopy showed higher resistances for RB of 4.2 Ω/cm−2 and RCT of 15.6 Ω/cm−2 compared to SiNPs anode. These findings suggest avenues for improving energy storage devices by selecting and designing suitable anode materials.

Silicon materials are currently being explored for usage in lithium–ion battery anodes due to their high lithium storage capacity,but their practical application is hindered by severe volume expansion during cycling, leading to mechanical degradation andcapacity fading. This study introduces a novel two-pot method for synthesizing silicon nanoparticles (Si NPs) to address thesechallenges. The method decouples precursor decomposition and nanoparticles deposition enabling in situ growth of Si NPs onnanographite substrates. By replacing hazardous silane precursors with polyvinyl alcohol or hydrogen gas, we eliminate safetyrisks while simplifying production. Scanning electron microscopy and electrochemical characterization confirm uniform Si NPdeposition. The fabricated electrodes displayed stable electrochemical performance with a capacity of 503 mAh/g after 100 cyclesin a half-cell configuration. This approach offers a safe route for producing high-performance silicon-based anodes.

Silicon materials are currently being explored for usage in lithium-ion battery anodes due to their high lithium storage capacity. We have developed a novel method, using a simple thermal treatment of low-cost silicon powder and nanographite, resulting in a composite where silicon nanoparticles are grown on the graphene surfaces. Electrodes fabricated from these Si-NG composites delivered a stable capacity of 489 mAh/g during 25 cycles, i.e. higher than conventional graphite anodes (theoretical capacity: 372 mAh/g). The method uses low-cost materials and avoids complex setups, thereby suggesting industrial scalability.