Spinel LiMn2O4 Nanorods via Template–Engaged Method and as Cathode Materials for Li-Ion Batteries

Spinel LiMn2O4 nanorods were prepared by a hydrothermal method followed by solid-state lithiation. The produce β-MnO2 nanowire as template, and LiOH·H2O was used as lithium source. The spinel LiMn2O4 nanorods samples were characterized by SEM, XRD, (HR)TEM, and galvanostatic charge/discharge profile measurement. Compared with the LiMn2O4 nanoparticles, the LiMn2O4 nanorods showed superior cycling stability, better rate capability, good high temperature performance, and delivered a discharge capacity of 122 mAh/g (at 1 C, 100 cycles).

Photo-assisted Charge/discharge Li-organic Battery with a Charge-separated and Redox-active C60@Porous Organic Cage Cathode

Photo-assisted Li-organic batteries provide an attractive approach for solar energy conversion and storage, while the challenge lies in the design of high-efficiency organic cathodes. Herein, a charge-separated and redox-active C60@porous...

Advances in Materials and Fabrication of Separators in Supercapacitors

Supercapacitors (SCs) have been extensively used in advanced energy applications due to their superior energy storage capacity and rapid charge – discharge rate. The significant constituents of a SC include...

Зависимость электрохимических параметров композитных SiO/C-анодов для литий-ионных аккумуляторов от состава и температуры синтеза

The results of a study of anodes obtained by carbonization of silicon monoxide by means of a reaction with solid-phase fluorocarbon CF0.8 are presented. Charge/discharge voltage profiles were studied at different currents depending on the composition and temperature of the synthesis of composites. The irreversible losses of the 1st cycle and the contribution to them of intrinsic losses due to the formation of lithium oxide and its silicates and losses associated with the formation of SEI are analyzed. A difference has been established in the behavior of anodes made of SiO carbonized by annealing with CF0.8 at T=800°C (SiO/C composite) and silicon monoxide annealed with CF0.8 at T>1000°C, at which disproportionation occurs simultaneously with the carbonization of SiO (d-SiO/C composite). The difference consisting in a higher discharge capacity, a higher Coulomb efficiency, and better rate capability of d-SiO/C is explained by a change in the composition of the SiOx matrix that occurs during the disproportionation process. The effect of the formation of d-SiO/C anodes by preliminary lithiation with a low current, after which the electrodes can be charged and discharged with much higher currents, has been discovered. The effect is explained by the amorphization of silicon crystallites and the increasing diffusion coefficient of lithium

Boundaries of charge-discharge curves of batteries

Understanding underlying mechanisms of charge-discharge behaviour of batteries, especially the intercalation Li-ion and Na-ion ones, is obligatory to develop and design the energy storage devices. The behaviour of the voltage-capacity/time...

Porous Fe2O3 nanorod-decorated hollow carbon nanofibers for high-rate lithium storage

Transition metal oxides (TMOs) are considered as promising anode materials for lithium-ion batteries in comparison with conventional graphite anode. However, TMO anodes suffer severe volume expansion during charge/discharge process. In this respect, a porous Fe2O3 nanorod-decorated hollow carbon nanofiber (HNF) anode is designed via a combined electrospinning and hydrothermal method followed by proper annealing. FeOOH/PAN was prepared as precursors and sacrificial templates, and porous hollow Fe2O3@carbon nanofiber (HNF-450) composite is formed at 450 °C in air. As anode materials for lithium-ion batteries, HNF-450 exhibits outstanding rate performance and cycling stability with a reversible discharge capacity of 1398 mAh g−1 after 100 cycles at a current density of 100 mA g−1. Specific capacities 1682, 1515, 1293, 987, and 687 mAh g−1 of HNF-450 are achieved at multiple current densities of 200, 300, 500, 1000, and 2000 mA g−1, respectively. When coupled with commercial LiCoO2 cathode, the full cell delivered an outstanding initial charge/discharge capacity of 614/437 mAh g−1 and stability at different current densities. The improved electrochemical performance is mainly attributed to the free space provided by the unique porous hollow structure, which effectively alleviates the volume expansion and facilitates the exposure of more active sites during the lithiation/delithiation process. Graphical abstract Porous Fe2O3 nanorod-decorated hollow carbon nanofibers exhibit outstanding rate performance and cycling stability with a high reversible discharge capacity.