Helical carbon nanofibers modified with Fe2O3 as a high performance anode material for lithium-ion batteries.

Helical carbon nanofibers (HCNFs) modified with Fe2O3 (Fe2O3/HCNFs) with a particle size of about 10-20 nm were first introduced for potential use as a novel anode material for lithium-ion batteries (LIBs). Fe2O3/HCNFs were successfully prepared via a chemical liquid deposition (CLPD) method in this study. HCNFs with a special three-dimensional helical structure improve the conductivity and also provide a strong supporting network space for stress and strain during the volume expansion of Fe2O3 nanoparticles. The Fe2O3/HCNF anode still retains its capacity of 816.3 mA h g-1 after 100 cycles at the current density of 200 mA g-1, which is significantly better than those of contrast samples (only 144.2 mA h g-1 for the bare Fe2O3, 241.2 mA h g-1 for HCNFs and 486.4 mA h g-1 for Fe2O3-HCNFs). These superior properties and facile preparation represent the potential of Fe2O3/HCNF anode materials for LIB application.

Modified Separator Using Thin Carbon Layer Obtained from Its Cathode for Advanced Lithium Sulfur Batteries.

The realization of a practical lithium sulfur battery system, despite its high theoretical specific capacity, is severely limited by fast capacity decay, which is mainly attributed to polysulfide dissolution and shuttle effect. To address this issue, we designed a thin cathode inactive material interlayer modified separator to block polysulfides. There are two advantages for this strategy. First, the coating material totally comes from the cathode, thus avoids the additional weights involved. Second, the cathode inactive material modified separator improve the reversible capacity and cycle performance by combining gelatin to chemically bond polysulfides and the carbon layer to physically block polysulfides. The research results confirm that with the cathode inactive material modified separator, the batteries retain a reversible capacity of 644 mAh g(-1) after 150 cycles, showing a low capacity decay of about 0.11% per circle at the rate of 0.5C.

An in situ self-developed graphite as high capacity anode of lithium-ion batteries.

Graphite with a large inter-planar distance (0.357 nm) was obtained from pig bone. It delivered an improving specific capacity which increased continuously to 538 mA h g(-1) at 1 A g(-1) after 1000 cycles. With microscopic characterization, it has been found that the pig-bone-based graphite was exfoliated to graphene during the charge-discharge process.