Laser‐Manufactured Metastable Supranano SnO_x for Efficient Electron/Ion Bridging in SnO₂‐Graphene Heterostructure Boosting Lithium Storage

Abstract

Robust anchoring of high-capacity nanocrystals (NCs) on porous conductive substrates is of paramount importance but it is challenging for highly efficient energy storage to prevent the weak interfacial interactions, inevitable aggregation, and sluggish charge transfer, due to the technical hurdles of constructing heterostructures with firm electron/ion bridging. Herein, a facile and highefficiency liquid-phase laser manufacturing strategy to guarantee the covalent bonding of ultrafine NCs on conductive substrates by predesigning metastable supranano (<10 nm) particles is proposed. The manufacturing of supranano SnO 2 (≈3.4 nm) is demonstrated to tightly anchor on mesoporous walls of graphene with high loading (≈81.3%) and homogenous dispersion. Such a optimized heterostructure with unimpeded electron/ion transfer delivers extraordinary long-term cycling stability (1132 mAh g -1 at 1.0 A g -1 after 1250 cycles) and impressive rate capability (275 mAh g -1 at 30.0 A g -1 ) as the anode for Li-storage, which are some of the highest values among the reported SnO 2 -based anodes. The study provides an important avenue for addressing the interfacial bridging in-between heterostructures via creating active metastable supranano particles for intriguing electrochemical applications or even beyond, based on laser-matter interactions.

Laser-Derived Interfacial Confinement Enables Planar Growth of 2D SnS2 on Graphene for High-Flux Electron/Ion Bridging in Sodium Storage

“…Experimentally, we achieve the synthesis of amorphous tin oxides (A-SnO x ) for pre-bonding by a modified procedure of laser manufacturing in liquid. It was reported in our previous work that crystalline SnO x could be generated from the irradiation of a non-focused pulsed laser beam (1064 nm, 10 Hz, 10 ns) [ 8 ], while in present study we placed polished Sn foil in thiourea aqueous solution upon laser irradiation. As schematically illustrated in Fig.…”

“…2 c and S1). Different from the case of laser irradiation of Sn in water [ 8 ], the irradiation of Sn in thiourea aqueous solution allows for oxidization of Sn upon both H 2 O and H 2 S, where both Sn-O and Sn-S bonds could form in the oxidation of Sn vapor. However, the generated Sn-S bond was eventually replaced by Sn-O bond owing to its lower binding energy (467 kJ mol −1 ) than that of Sn-O (528 kJ mol −1 ).…”

“…The formation of the amorphous supranano SnO x can thus be ascribed to the competitive bonding between Sn-O and Sn-S, which would deepen the crystallization disorder of laser-manufactured particles, as depicted in Fig. 2 d, thus differing from the case of generating crystalline SnO x NPs in aqueous solution [ 8 ].

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“…S3d) [ 35 , 37 ]. It should be noted that the obtained A-SnO x NPs are expected to prebond easily on reduced graphene oxide (rGO) with covalent bonds, benefitting from the extremely high reactivity enabled by the amorphous phase and abundant oxygen vacancies, as demonstrated in our recent experiment and theoretical simulation [ 8 ]. Moreover, the generated A-SnO x colloids have positively charged surface (+ 11.7 mV) (Fig.…”

“…Compared with SnS 2 /G and rGO, the adsorption peaks corresponding to the C-O and C=C bonds in A-SnS 2 @G downshift to 1188 and 1565 cm −1 . It can also be observed that the C=O bond disappears, implying the robust C-S-Sn coupling effect between SnS 2 and rGO [ 8 , 17 ]. Hence, a strong interfacial interaction with face-to-face contact was constructed in the A-SnS 2 @G.…”