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Transition metal sulfides appear excellent electrochemical properties in the realm of anode for sodium-ion batteries and hold significant potential for practical application in large-scale devices in the future. However, their development is hindered by inferior inherent conductivity and tremendous volume strain during discharge and charge processes. In this study, Co 1-x S@C nanoboxes were synthesized utilizing Co-Co PBA as a precursor. The electrochemical sodium storage performance of Co 1-x S@C electrode was characterized, revealing an extremely long-life and stable performance. At 1.0 A g−1 and 2.0 A g−1, the electrode delivered capacities of 255.8 mAh g−1 and 197.6 mAh g−1 after 5000 and 10,000 cycles respectively, with negligible capacity attenuation. The pseudo-capacitance behavior of Co 1-x S@C NBs electrode in sodium storage was quantitatively calculated through CV test at varying sweep speeds. The significant contribution of pseudo-capacitance resulted in its exceptional rate capacity and electrochemical stability. Furthermore, kinetic analysis revealed that the existence of a carbon shell enhanced the Na+ diffusion kinetics and charge transfer kinetics of Co 1-x S@C NBs. This strategy provides a reference for enhancing the Na+ storage performance of other transition metal sulfides. [ABSTRACT FROM AUTHOR]

• ZnS-MoS 2 /rGO composites were synthesized by using a one-step high-temperature mixing method (HTMM) under hydrothermal conditions. • The synthesis approach is implemented by using the self-designed dual-chamber Teflon lined reactor and ingenious rotation process. • The synergistic effect in the hybrid enhances electronic conductivity and structural stability. • The ZnS-MoS 2 /rGO@C composites with large proportion of pseudocapacitive contribution exhibits excellent rate capability. Hybrid-structured coupling metal dichalcogenides with carbon materials serve as prospective anode materials for lithium-ion batteries (LIBs) due to their high electrical conductivity, rich active sites, and Li+ diffusion path for Li+ storage. In the present work, graphene-wrapped ZnS−MoS 2 @carbon composites (ZnS−MoS 2 /rGO@C) are synthesized via high-temperature mixing during the hydrothermal and carbonation processes. The as-prepared ZnS−MoS 2 /rGO@C composites display alleviated volume change in the electrochemical process, increased Li+ diffusion speed, and improved conductivity, which are caused by the synergic effect of phase boundaries and hierarchical construction. Therefore, the ZnS−MoS 2 /rGO@C composites show superior lithium storage capacity and structure stability, and possess ultrastable cycle (581.0 mAh g−1 after 500 cycles at 1 A g−1) and good rate performance (310.7 mAh g−1 at 5 A g−1). This work confirms that anode materials with a hybrid structure can be rationally engineered for high-performance LIBs with superior cycle durability and good rate capability. [Display omitted] [ABSTRACT FROM AUTHOR]

• PEO-based 3D CPE-5 was prepared by reinforcing with PVDF-HFP nanofibers and LATP particles. • The thickness of 3D CPE-5 is only 50 μm with excellent mechanical strength. • 3D CPE-5 displays high electrochemical window (5.21 V) and lithium transference number (0.49). • 3D CPE-5 shows excellent stability to Li-metal and effective lithium dendrite inhibition. • High-voltage Li/3D CPE-5/NCM811 battery shows excellent cycling stability at 0.1 and 0.5 c. Solid-state lithium metal batteries (SSLMBs) are considered as a promising energy storage technology due to their high energy density and safety. However, the relatively low conductivity of solid-state electrolytes and the high electrolyte–electrode interfacial resistance seriously limited the development of SSLMBs. In this work, the high-performance PEO-based composite polymer electrolyte (3D CPE-5) was successfully prepared by reinforcing with polyvinylidene fluoride–hexafluoropropylene nanofibers and Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP) particles. The thickness of 3D CPE-5 is only 50 μm with high electrochemical window (5.21 V) and lithium transference number (0.49) at 60 ℃. In addition, the 3D CPE-5 shows excellent stability to Li–metal, so that Li–Li symmetric cells can run stably for more than 300 h under 0.1 mA cm−2 with low voltage polarization value (15 mV) and effective lithium dendrite inhibition. Finally, the high-voltage Li/3D CPE-5/NCM811 (LiNi 0.8 Co 0.1 Mn 0.1 O 2) solid-state battery demonstrates excellent cycling stability at 0.1 and 0.5 C (60 ℃). The excellent safety performance of 3D CPE-5 highlights its remarkable advantages over liquid electrolytes and provide an effective design strategy of high-performance polymer electrolytes for SSLMBs. [Display omitted] [ABSTRACT FROM AUTHOR]

Rapid developments in revolutionary electric vehicles have led to an increase in the energy-density and cycling-life requirements for Li-ion batteries (LIBs). The binary transition metal oxide NiCo 2 O 4 is attracting considerable attention due to its much larger specific capacity than graphite. However, NiCo 2 O 4 suffers from poor cycling performance owing to a large volume change during cycling. To address this problem, we proposed an easy strategy to fabricate in situ carbon-coated NiCo 2 O 4 bilayered hybrid nanostructural arrays supported on Ni foam (denoted as NiCo 2 O 4 @C BHNAs–NF) as free-standing anodes for LIBs through a sucrose-assisted hydrothermal method. The in situ-synthesized uniform carbon shell can simultaneously buffer the volume change during cycling and increase the conductivity. The micro/nano-structure also possessed outstanding structural advantages, such as large surface area and hierarchical porous characters, enabling NiCo 2 O 4 @C BHNAs–NF to have excellent electrochemical performance. Its capacity can reach 1298 mAh/g at a current density of 100 mA/g, and 86% of the initial capacity can be retained after 100 cycles. All these results revealed that NiCo 2 O 4 @C BHNAs–NF was a promising candidate anode for next-generation LIBs. [ABSTRACT FROM AUTHOR]

With the wearable electronics progressing rapidly, the demand for flexible, long-life and low-cost electrodes of Li-ion batteries (LIBs) becomes more and more urgent. Due to the abundant resources and low cost, silica (SiO 2 ), especially the amorphous one, has attracted a lot of interests on the application of anode materials for LIBs. However, SiO 2 still suffer from the poor cycling performance mainly caused by the huge volume change during cycling like other alloy-type materials. Furthermore, it remains a challenge to fabricate the SiO 2 –based flexible electrode. Herein, we propose a facile in situ strategy to fabricate the electrospun robust free-standing SiO 2 /carbon nanofibers (denoted as in-SCNFs) film constructed by N-doped carbon nanofibers encapsulating uniformly amorphous SiO 2 nanoparticles. The in situ synthesized finer SiO 2 nanoparticles in the in-SCNFs are uniformly encapsulated in flexible carbon nanofibers, which can effectively buffer the volume change. Furthermore, the robust in-SCNFs film possesses the excellent mechanical flexibility and strength. So, when served as the free-standing anode of LIBs, the in-SCNFs film exhibits superior cycling performance. A discharge specific capacity of 405 mAh/g can be delivered even after a long-term 1000 cycles at a large current density of 500 mA/g, and the retention is up to 115%. It is an exciting finding that the in-SCNFs film is also a long-life anode of Na-ion batteries (NIBs). The 99% of initial capacity can be kept after 250 cycles at 500 mA/g. To our best knowledge, this is the first report on the application of SiO 2 /C composite for NIBs. These results suggest that the as-fabricated in-SCNFs film can become one promising free-standing long-life anode for LIBs and NIBs. [ABSTRACT FROM AUTHOR]