Stress-Relief Network in Silicon Microparticles and Composite Anodes for Durable High-Energy-Density Batteries

Abstract

Silicon microparticles (SiMPs), which have a high capacity, a high initial Coulombic efficiency, and a low volume-to-surface ratio compared with nanosized materials, are promising anode materials for high-energy-density battery applications. However, SiMPs suffer from inevitable particle pulverization and electrode failure at the early cycle. In this study, we suggest the construction of a porous, stress-relief carbon network on the surface of each SiMP to alleviate particle degradation at the electrode level through a template-free co-reaction of thermal polymer pyrolysis and graphitization. The designed porous graphitic carbon network (pGN) structure features not only considerable electrical conductivity and expansion tolerance but also sturdy SiMP interconnection during cycling. This enables SiMPs to improve battery performance and achieve high Coulombic efficiency and a stable cycle life in fast-charging systems without particle dissipation. Moreover, the composite anode comprising a practical level of commercial graphite and SiMP contents with pGN operates effectively because of high cycle efficiency and structural integrity, which promises the realization of advanced battery applications.

Wrapping silicon microparticles by using well-dispersed single-walled carbon nanotubes for the preparation of high-performance lithium-ion battery anode

“…4a, the sharp peak in the Raman spectrum of SiMP at around 500 cm-1 corresponds to crystalline Si. 4,31 In addition, the SWCNTs show a Raman spectrum with distinctive peaks. The peaks at the low wavenumber side at around 1350 cm −1 and at around 1590 cm −1 are derived from the radial breathing mode (RBM), defect, and inplane vibration of a six-membered ring of carbon materials, respectively.…”

“…The distinct anodic and cathodic peaks of Si are observed. 3,4,39,40 In detail, the cathodic peaks around 0.2 and 0.01 V correspond to the lithiation of Si. 9 In the anodic scan, two peaks at around 0.3 and 0.5 V are related to the de-lithiation process from the Li-Si alloy to amorphous silicon.…”

“…[1][2][3] Silicon (Si) anodes are considered one of the promising anode materials for next-generation lithium-ion batteries (LIBs) due to their superior theoretical specic capacity (>4000 mA h g −1 ) and low working potential (∼0.3 V vs. Li/Li + ). 1,2,4 To be specic, cost-effective micron-scale silicon could become more competitive in future research work and applications. [4][5][6] However, the high capacity of Si, which originates from the alloying mechanism, introduces the failure mechanisms of active material pulverization (∼300%), electrode delamination, and continuous solid electrolyte interphase (SEI) layer growth.…”

“…1,2,4 To be specic, cost-effective micron-scale silicon could become more competitive in future research work and applications. [4][5][6] However, the high capacity of Si, which originates from the alloying mechanism, introduces the failure mechanisms of active material pulverization (∼300%), electrode delamination, and continuous solid electrolyte interphase (SEI) layer growth. 1,2 Furthermore, another critical problem of Si anodes is their intrinsically low electrical conductivity (∼10 −3 S m −1 ).…”

Practical production of heteroatom-bridged and mixed amorphous–crystalline silicon for stable and fast-charging batteries

“…4 From an electroactive material standpoint, conventional graphite anodes have been saturated due to their low theoretical capacity (372 mA h g −1 ), which cannot meet the rising demand for high-energy-density batteries. 5,6 Among many candidates of anode materials for higher-energy-density realization, alloy-type materials like silicon (Si), 7 germanium (Ge), 8 tin (Sn), 9 and antimony (Sb) 10 have been in the limelight as alternative materials because of their intrinsically high theoretical capacity based on their reaction mechanism. The Si-based anode, in particular, is considered as one of the most promising materials for overcoming the limitation of energy density owing to its high theoretical capacity (3579 mA h g −1 for Li 15 Si 4 ), low operation voltage (<0.4 V versus Li/Li + ), natural abundance, and well-established structure.…”