Xiaozhong Zhou,Zhengfeng Zhang,Xiaohu Xu,Jian Yan,Guofu Ma,Ziqiang Lei
Sb6O13/reduced graphene oxide (Sb6O13/rGO) nanocomposite was synthesized by the solvothermal method using Sb2O3 and graphene oxide as raw material. On the basis of the physical and electrochemical characterizations, Sb6O13 nanocrystals of 10–20 nm size were uniformly anchored on rGO sheets, and the nanocomposite displayed a large reversible specific capacity of 1271 mA h g–1 and an excellent cyclability of 1090 mA h g–1 after 140 cycles at 100 mA g–1 when proposed as a potential anode material for lithium ion batteries, emphasizing the advantages of anchoring of Sb6O13 nanocrystals on rGO sheets for the maximum utilization of electrochemically active Sb6O13 and rGO for lithium storage.
Xiaozhong Zhou,Xiaoyan Zheng,Hejie Lu,Hongling Deng,Zheyi Liu,Jiangwei Deng
Antimony oxides are of great promise for lithium storage due to their high theoretical capacity, but low intrinsic conductivity and large volume change during lithium-ion insertion/extraction lead to inferior cycling stability. Herein, Sb 6 O 13 nanocrystals were successfully embedded in three-dimensional (3D) honeycomb-like reduced holey graphene oxides (HrGO) sheets by H 2 O 2 -assisted solvothermal method, and the as-synthesized Sb 6 O 13 /HrGO composite was demonstrated to deliver superior electrochemical lithium-storage performance. During the preparation process, graphene oxides (GO) sheets were pretreated with H 2 O 2 to boost formation of in-plane nanoholes, which play crucial roles in both constructing Sb 6 O 13 /HrGO with unique 3D honeycomb-like structure and boosting lithium-storage kinetics. 3D interconnect HrGO sheets with honeycomb-like structure construct a stereoscopic conductive network skeleton for fast electron transfer and alleviating volume expansion of active components during charging/discharging process. Moreover, abundant in-plane nanoholes enable lithium ions to migrate cross graphene sheets, resulting in shortening diffusion distance and fastening diffusion kinetics. Thus, Sb 6 O 13 /HrGO electrode exhibited a high reversible capacity of 956.1 mA h g −1 (200 mA g −1 ) based on conversion-alloying mechanism and superior high-rate capability (493.4 mA h g −1 at 1000 mA g −1 ) for lithium storage. This work provides a facile, environmental-friendly and scalable strategy to fabricate composites with special structures for high-rate energy storage.
This investigation employed high-temperature drop calorimetry to determine the high-temperature heat capacities ( C p ) of Sb 6 O 13 and three polymorphs of perovskite-type Ca 6 Sb 2 O 11-δ : cubic (Cub), tetragonal (Tet), and orthorhombic (Orth). The temperature-dependent C p relationships for Sb 6 O 13 , Cub-Ca 6 Sb 2 O 11 , Tet-Ca 6 Sb 2 O 11 and Orth-Ca 6 Sb 2 O 11-δ were derived as: C p (Sb6O13) = 493.05 + 6.61 × 10 −11 T -9498750 T −2 (573–973 K); C p (Cub-Ca6Sb2O11) = 550 + 2.00× 10 −6 T −22848000 T −2 (573–1273 K); C p (Tet-Ca6Sb2O11) = 481.03 + 1.92 × 10 −9 T -7780332.5 T −2 (573–1273 K); C p (Orth-Ca6Sb2O11-δ) = 492.474 + 3.63× 10 −9 T− 8940348.47 T −2 (573–1273 K), and then used for computing changes in entropy and Gibbs free energy.
Shuang Liao,Xiaowen Wang,Huawen Hu,Dongchu Chen,Min Zhang,Jie Luo
In this communication, nano-thin carbon-encapsulated Sb 6 O 13 nanoparticles (Sb 6 O 13 NPs@C) synthesized innovatively in a one-pot manner were demonstrated as a high-performance anode material for Na-ion batteries. The synthesized Sb 6 O 13 NPs@C bearing irregular nanopores showed an average size of around 60 nm and possessed the 13.6 wt% carbon shell composition, with the mesopores generated by the Sb 6 O 13 NPs@C aggregation. The as-assembled Na-ion battery with Sb 6 O 13 NPs@C exhibited both excellent rate performance (the capacity of as high as 239 mA h g −1 at a current density of 1000 mA g −1 ) and cycling stability (89.64% capacity retained after 170 cycles). The in-depth understanding of the working principle of the Sb 6 O 13 NPs@C nanocomposite anode for the Na-ion battery was also provided.
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