Search

Abstract Recently, in order to increase the electrical conductivity of the phosphorus-based anode materials and to alleviate the deterioration of the electrochemical performance caused by the volume expansion of red phosphorus, the composite material made of red phosphorus and carbon matrix has become the mainstream route for lithium ion batteries. In this work, we used one-pot ball milling method to synthesize an unique rebar-reinforced concrete structure hybrid of nanosized phosphorus particles, multi-walled carbon nanotubes, and carbon black (CNTs/CB@P composites). The carbon nanotubes formed a primary frame network structure and the CB formed a regional secondary network structure in the CNTs/CB@P composites, which makes red phosphorus covered by double network structure. Such a structure greatly improves the conductive network of CNTs/CB@P composites for lithium ion batteries. Furthermore, this one-pot ball milling method was simple, continuous, and much suitable for industrial production. When the ratio of multi-walled carbon nanotubes to carbon black was 3:2, the CNTs/CB@P composites had the cycling performance with a reversible capacity of ~ 474.9 mAh g−1 and a capacity retention of ~ 56.3% after 50 cycles. [ABSTRACT FROM AUTHOR]

A flexible and free-collector-current of silicon-based anode is facilely prepared just by coating carbon black (CB) and silicon powders layer-by-layer. The resultant electrodes with a “sandwich” structure (CB/Si/CB) are assembled into half-cell and its electrochemical properties are tested. This type of anode exhibits excellent cycling and outstanding rate capability. The superior electrochemical performances are ascribed to both flexible CB-layers to offset the volume expansion of Si-particle. And, the CB-layer with high electric conductivity can provide efficient electron conductive pathways when Si particles react with lithium. More importantly, the CB/Si/CB electrodes without the collerctor (copper-foil) are exhibited high energy density, due to the weight proportion of copper foil is exceeded 60%. The CB/Si/CB electrode is used to assemble full-cell with the same structure as free-collector LCO/CB cathode material. It imposes the energy density of 200 Wh kg −1 , and can keep stable charging-discharging capability at various deformations of shapes. And the flexible-cell of high performance is obtained to meet diverse applications in energy storage devices. Until now, many flexible batteries are put forward by researchers, but these product is faced with the complex production-process, high-cost material, low energy-density. This CB/Si/CB structure is produced with the matching current manufacturing industry and the common raw material, and to get a full-cell of the high energy density. [ABSTRACT FROM AUTHOR]

To improve the electrochemical performance of Na 2 Li 2 Ti 6 O 14 , carbon black (CB), graphene (GN) and carbon nanotube (CNT) are introduced to fabricate high conductive Na 2 Li 2 Ti 6 O 14 /CB, Na 2 Li 2 Ti 6 O 14 /GN, Na 2 Li 2 Ti 6 O 14 /CNT and Na 2 Li 2 Ti 6 O 14 /CB/GN/CNT by a solid state method. It can be found that only CNT forms a complete three-dimensional conductive network which embeds the randomly distributed Na 2 Li 2 Ti 6 O 14 particles, leading to an improvement of electronic conductivity. The results of cyclic voltammetry, electrochemical impedance spectroscopy and charge–discharge tests reveal that Na 2 Li 2 Ti 6 O 14 /CNT obtains the lowest redox polarization and the highest peak current among all the five samples. As a result, Na 2 Li 2 Ti 6 O 14 /CNT shows the best cycling and rate performances among all the five samples. It reveals a charge capacity of 111.4 mAh g −1 at 100 mA g −1 , 110 mAh g −1 at 200 mA g −1 , 103.9 mAh g −1 at 300 mA g −1 and 98.9 mAh g −1 at 400 mA g −1 . For comparison, bare Na 2 Li 2 Ti 6 O 14 only displays a charge capacity of 89.9 mAh g −1 at 100 mA g −1 , 79.7 mAh g −1 at 200 mA g −1 , 73.7 mAh g −1 at 300 mA g −1 and 69.4 mAh g −1 at 400 mA g −1 . It indicates that the introduction of CNT is more effective to improve the performance of Na 2 Li 2 Ti 6 O 14 than CB, GN and CB/GN/CNT. [ABSTRACT FROM AUTHOR]

As a novel anode material for lithium-ion batteries, Pb(NO3)2can deliver an initial discharge capacity as high as 1310.8 mAh g−1. However, its capacity retention is poor upon repeated cycles. In this work, carbon black (CB), graphene (GN) and carbon nanotube (CNT) are used as conductive additives to fabricate Pb(NO3)2/CB, Pb(NO3)2/GN and Pb(NO3)2/CNT, respectively. It is observed that CB and GN fail to form uniform three-dimensional conductive network for Pb(NO3)2. As a result, Pb(NO3)2/CB and Pb(NO3)2/GN do not show obviously improved electrochemical properties compared to bare Pb(NO3)2. For comparison, CNTs provide cross-linking conductive cages for Pb(NO3)2particles. It can be found that CNT coating can significantly enhance the electrochemical property of Pb(NO3)2. Pb(NO3)2/CNT reveals a reversible charge capacity of 495.2 mAh g−1after 45 cycles at a current density of 50mAg−1, which is much higher than that of bare Pb(NO3)2(227.4 mAh g−1), Pb(NO3)2/CB (278.0 mAh g−1), Pb(NO3)2/GN (327.2 mAh g−1). Even cycled at 200mAg−1, Pb(NO3)2/CNT can maintain a reversible lithium storage capacity of 411.7 mAh g−1. All these results suggest that Pb(NO3)2/CNT is a promising anode material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: The hybrid LiNi0.5Mn1.5O4/C cathode material is prepared with a facile method of pre-mixing and post-calcination treatment for enhancing the rate performance. The physical and electrochemical properties are discussed through X-ray diffraction (XRD), transmission electron microscopy (TEM), charge–discharge measurements in test cells and electrochemical impedance spectroscopy (EIS). The results show that the LiNi0.5Mn1.5O4 particle can be partially surrounded and interconnected with each other by carbon black particles, therefore the electronic conductivity can be remarkably improved by over 5 times without degrading the spinel structure. The LiNi0.5Mn1.5O4/C composite exhibits enhanced rate capability together with cycling performance compared to LiNi0.5Mn1.5O4. EIS confirms that the significantly improved electrochemical property is due to the suppression of surface resistance and the enhanced electronic conductivity. [Copyright &y& Elsevier]