Chao Jin

As high-capacity anode materials, spinel NiFe₂O₄ aroused extensive attention due to its natural abundance and safe working voltage. For widespread commercialization, some drawbacks, such as rapid capacity fading and poor reversibility due to large volume variation and inferior conductivity, urgently require amelioration. In this work, NiFe₂O₄/NiO composites with a dual-network structure were fabricated by a simple dealloying method. Benefiting from the dual-network structure and composed of nanosheet networks and ligament-pore networks, this material provides sufficient space for volume expansion and is able to boost the rapid transfer of electrons and Li ions. As a result, the material exhibits excellent electrochemical performance, retaining 756.9 mAh g⁻¹ at 200 mA g⁻¹ after cycling for 100 cycles and retaining 641.1 mAh g⁻¹ after 1000 cycles at 500 mA g⁻¹. This work provides a facile way to prepare a novel dual-network structured spinel oxide material, which can promote the development of oxide anodes and also dealloying techniques in broad fields.

Metal oxide anode materials are affected by severe volume expansion and cracking in the charging/discharging process, resulting in low capacity and poor cycle stability, which limits their application in lithium-ion batteries (LIBs). Herein, a new strategy is uncovered for a preparing spinel-structured, multi-component transition metal oxide, (Ni,Co,Mn)Fe₂O_4−x, with oxygen vacancies as an LIB anode material. The as-fabricated material presented excellent reversible capacity and cycling stability, delivering a discharge capacity of 1240.2 mAh g⁻¹ at 100 mA g⁻¹ for 200 cycles and then at 300 mA g⁻¹ for 300 additional cycles. It presented extremely long cycle stability even at 2 A g⁻¹, revealing 650.5 mAh g⁻¹ after 1200 cycles. The good lithium storage capacity can be ascribed to the entropy stabilization effect, the multi-cation synergistic effect, abundant oxygen vacancies and the spinel structure. This study provides a new opportunity to fabricate and optimize conversion-type anodes for LIBs with satisfactory electrochemical performance.

Biodegradable Mg–Zn–Ca-based metallic glasses (MGs) present improved strength and superior corrosion resistance, compared to crystalline Mg. In particular, in vivo and in vitro attempts reveal that biodegradable Mg–Zn–Ca-based MGs possess excellent biocompatibility, suggesting that they are ideal candidates for temporary implant materials. However, the limited size and severe brittleness prevent their widespread commercialization. In this review, we firstly summarize the microstructure characteristic and mechanical properties of Mg–Zn–Ca-based MGs. Then, we provide a comprehensive and systematic understanding of the recent progress of the biocorrosion and biocompatibility of Mg–Zn–Ca-based MGs. Last, but not least, the outlook towards the fabrication routes, composition design, structure design, and reinforcement approaches of Mg–Zn–Ca-based MGs are briefly proposed.

By virtue of the high theoretical capacity of Si, Si-related materials have been developed as promising anode candidates for high-energy-density batteries. During repeated charge/discharge cycling, however, severe volumetric variation induces the pulverization and peeling of active components, causing rapid capacity decay and even development stagnation in high-capacity batteries. In this study, the Si/Fe₂O₃-anchored rGO framework was prepared by introducing ball milling into a melt spinning and dealloying process. As the Li-ion battery (LIB) anode, it presents a high reversible capacity of 1744.5 mAh g⁻¹ at 200 mA g⁻¹ after 200 cycles and 889.4 mAh g⁻¹ at 5 A g⁻¹ after 500 cycles. The outstanding electrochemical performance is due to the three-dimensional cross-linked porous framework with a high specific surface area, which is helpful to the transmission of ions and electrons. Moreover, with the cooperation of rGO, the volume expansion of Si is effectively alleviated, thus improving cycling stability. The work provides insights for the design and preparation of Si-based materials for high-performance LIB applications.