Search

For the poor capacity utilization and insufficient cyclability of TiO 2 /C anodes for lithium-ion batteries, we synthesized branch-like TiO 2 @mesoporous carbon nanofibers (TiO 2 @MCNFs) as free-standing anodes via electrospinning technique, hydrothermal treatment and a subsequent carbonization process, where anatase TiO 2 branches were densely embedded on the mesoporous carbon nanofiber trunks. Due to the copious highly-exposed TiO 2 nanocrystal lattices on the branch except for the trunk support, the abundant intrinsic crystal channels for fluent Li + transportation, and the interlaced carbon nanofiber framework with a high structural integrity and mechanical flexibility, the branch-like TiO 2 @MCNFs composites presented a superior initial discharge capacity of 1932 mAhg −1 and an excellent reversible capacity of ∼617 mAhg −1 after 100 cycles. And compared with those of the reported TiO 2 /C electrodes, the initial discharge capacity and reversible capacity of the branch-like TiO 2 @MCNFs composites increased by ∼2 times and ∼50%, respectively. Hence, the unique architecture of the branch-like TiO 2 @MCNFs composites and their superior electrochemical performances may provide new insights for the development of better host materials for practical lithium-ion batteries. [ABSTRACT FROM AUTHOR]

With a high theoretical specific and typical self-healing mechanism, Sn 4 P 3 alloy has been widely concerned as an anode material for sodium-ion batteries (SIBs). The mechanism is attributed to a reversible conversion reaction combined with an alloy reaction. Essentially, Sn nanoparticles act as an electronic channel to activate the P component. Meanwhile, P and Na 3 P play a matrix to partially restore the degradation and aggregation of the alloy. Nevertheless, pure Sn 4 P 3 inevitably shortens the cycle life due to volume expansion. Herein, the puffed rice hard carbon (HC) with loose structure within the temperature range from 800 °C to 1400 °C is used to tightly wrap the alloy via a simple ball milling. The structurally stable Sn 4 P 3 @HC composites improve the electrochemical performance of SIBs. At 1000 °C, the composites show an excellent reversible capacity of 430 mA h g−1 at 100 mA g−1 over 100 cycles, with an elevated rate capability of 260 mA h g−1 even at 3.0 A g−1, and a high capacity of 312 mA h g−1 after 400 cycles at 1.0 A g−1. This work not only testifies a superior design of HC and alloy which synergistically stabilize the electrochemical performance of SIBs, but also provides a simple, efficient, and easy-to-scale coating method for active materials. Image 1 • Structurally stable Sn 4 P 3 particles coated with HC are prepared by ball milling. • The structure and d -spacing of HC formed at different temperatures are investigated. • The Sn 4 P 3 @HC composites exhibit excellent electrochemical performances. • The co-storage mechanism of self-healing Sn 4 P 3 and HC is researched. [ABSTRACT FROM AUTHOR]