Constraining Si Particles within Graphene Foam Monolith: Interfacial Modification for High‐Performance Li⁺ Storage and Flexible Integrated Configuration

Abstract

Pulverization of electrode materials and loss of electrical contact have been identified as the major causes for the performance deterioration of alloy anodes in Li‐ion batteries. This study presents the hierarchical arrangement of spatially confining silicon nanoparticles (Si NPs) within graphene foam (GF) for alleviating these issues. Through a freeze‐drying method, the highly oriented GF monolith is engineered to fully encapsulate the Si NPs, serving not only as a robust framework with the well‐accessible thoroughfares for electrolyte percolation but also a physical blocking layer to restrain Si from direct exposure to the electrolyte. In return, the pillar effect of Si NPs prevents the graphene sheets from restacking while preserving the highly efficient electron/Li+ transport channels. When evaluated as a binder‐free anode, impressive cycle performance is realized in both half‐cell and full‐cell configurations. Operando X‐ray diffraction and in‐house X‐ray photoelectron spectroscopy confirm the pivotal protection of GF to sheathe the most volume‐expanded lithiated phase (Li15Si4) at room temperature. Furthermore, a free‐standing composite film is developed through readjusting the pore size in GF/Si monolith and directly integrated with nanocellulose membrane (NCM) separator. Because of the good electrical conductivity and structural integrity of the GF monolith as well as the flexibility of the NCM separator, the as‐developed GF/Si‐NCM electrode showcases the potential use in the flexible electronic devices.

Bimetal-Organic-Framework Derivation of Ball-Cactus-Like Ni-Sn-P@C-CNT as Long-Cycle Anode for Lithium Ion Battery

“…However, the commercial graphite anode exhibits a low theoretical capacity of only 372 mA h g −1 . To address this issue, numerous investigations have been made to explore and design new anode materials with high capacity and long cycle life, such as Si, Sn, transitional metal oxides and sulfides . Among many classes of alternative anode materials, metal phosphides seem to be a new potential to replace graphite due to their low polarization, minor electrode volume expansion, and high gravimetric capacity based on either intercalation or conversion reactions .…”

Catalytic Growth of Graphitic Carbon‐Coated Silicon as High‐Performance Anodes for Lithium Storage

“…Raman spectroscopy (Figure d) of p‐SiNSs@C‐2 exhibits a disorder‐induced D band and a graphitic G band. The calculated I D / I G of silicon composite is ≈0.55, demonstrating that the carbon layer has a high degree of graphitization and a high electronic conductivity . In addition, the two peaks located at 512 and 940 cm −1 are the characteristic peaks of nanosilicon .…”

Integrated Thin Film Battery Design for Flexible Lithium Ion Storage: Optimizing the Compatibility of the Current Collector‐Free Electrodes

“…The Raman spectra of various rGO‐MoS 2 /NC composites were compared in Figure f. For all the composites, there exist two broad peaks at Raman shifts of 1371 and 1593 cm −1 , assignable to the in‐plane vibrations of SP 3 amorphous carbon (D band) and SP 2 graphic carbon (G band), respectively . Noted that the I D /I G value gradually increased from 0.81 to 1.01, indicating the reduced graphitization degree among the composites upon the heavier dosage of rGO component .…”