The lithium-ion exchange rate capability of various commercial graphite materials are evaluated using galvanostatic charge/discharge cycling in a half-cell configuration over a wide range of C-rates (0.1 similar to 60C). The results confirm that graphite is capable of de-intercalating stored charge at high rates, but has a poor intercalating rate capability. Decreasing the graphite coating thickness leads to a limited rate performance improvement of the electrode. Reducing the graphite particle size shows enhanced C-rate capability but with increased irreversible capacity loss (ICL). It is demonstrated that the rate of intercalation of lithium-ions into the graphite is significantly limited compared with the corresponding rate of de-intercalation at high C-rates. For the successful utilisation of commercially available conventional graphite as a negative electrode in a lithium-ion capacitor (LIC), its intercalation rate capability needs to be improved or oversized to accommodate high charge rates.

Rate capability of graphite materials as negative electrodes in lithium-ion capacitors

Multifunctionalization of carbon nanotubules is easily achieved by attaching functional molecules that provide specific advantages for microscopic applications. We fabricated a double photodynamic therapy (PDT) and photohyperthermia (PHT) cancer phototherapy system that uses a single laser. Zinc phthalocyanine (ZnPc) was loaded onto single-wall carbon nanohorns with holes opened (SWNHox), and the protein bovine serum albumin (BSA) was attached to the carboxyl groups of SWNHox. In this system, ZnPc was the PDT agent, SWNHox was the PHT agent, and BSA enhanced biocompatibility. The double phototherapy effect was confirmed in vitro and in vivo. When ZnPc-SWNHox-BSA was injected into tumors that were subcutaneously transplanted into mice, the tumors almost disappeared upon 670-nm laser irradiation. In contrast, the tumors continued to grow when only ZnPc or SWNHox-BSA was injected. We conclude that carbon nanotubules may be a valuable new tool for use in cancer phototherapy.

Fabrication of ZnPc/Protein Nanohorns for Double Photodynamic and Hyperthermic Cancer Phototherapy

A Review of the Design of Advanced Binders for High-Performance Batteries

Metal oxide nanowires for chemiresistive gas sensors: Issues, challenges and prospects

Hierarchical Cr-doped WO3 microspheres have been successfully synthesized for efficient sensing of H2S gas at low temperatures. The hierarchical structures provide an effective gas diffusion path via well-aligned micro-, meso-, and macroporous architectures, resulting in significant enhancement in sensing response to H2S. The temperature and gas concentration dependence on the sensing properties elucidate that Cr dopants remarkably improve the response and lower the sensor’ operating temperature down to 80 °C. Under 0.1 vol % H2S, the response of Cr-doped WO3 sensor is 6 times larger than pristine WO3 sensor at 80 °C. We suggest the increasing number of oxygen vacancies created by Cr dopants to be the underlying reason for enhancement of charge carrier density and accelerated reactions with H2S.

Low-Temperature H2S Detection with Hierarchical Cr-Doped WO3 Microspheres

A Novel α‐MoO 3 /Single‐Walled Carbon Nanohorns Composite as High‐Performance Anode Material for Fast‐Charging Lithium‐Ion Battery

In the ongoing pursuit toward a high-performance lithium-ion battery (LIB), an understanding of the solid electrolyte interface (SEI) layer is important to enhance the performance and lifetime of L...

In Situ/ex Situ Investigations on the Formation of the Mosaic Solid Electrolyte Interface Layer on Graphite Anode for Lithium-Ion Batteries

Aqueous binders are preferred over non-aqueous binders for lithium-ion batteries electrode fabrication process due to environmentally benign and low cost as they do not require humidity-controlled conditions. Herein, for the first time, polyvinyl alcohol and sodium alginate are used as aqueous binders in the preparation of lithium-titanium oxide anode for lithium-ion batteries. Electrodes have been prepared by varying the binder content from 3 to 5 wt% and are characterized by XRD, SEM, XPS, peel strength, and impedance analyzer. The electrodes with 3 wt% polyvinyl alcohol and 4 wt% sodium alginate content exhibited the initial discharge capacities of 130 and 104 mAhg−1 at 1C-rate with 96 and 93% capacity retention after 500 cycles, respectively. Whereas, the electrode with 4 wt% polyvinylidene fluoride binder delivered 135 mAhg−1 with 77% capacity retention after 500 cycles. In addition, the anode with 3 wt% polyvinyl alcohol binder delivers a discharge capacity as high as 80 mAhg−1 at 5C-rate. The lithium-titanium oxide electrode with polyvinyl alcohol binder showed the higher lithium-ion diffusion coefficient and lower polarization than that of sodium alginate and polyvinylidene fluoride binders, which resulted in a better capacity, cyclic stability and rate capability. Hence, polyvinyl alcohol and sodium alginate can be used as potential aqueous binders for lithium-titanate oxide anode.

Investigation on polyvinyl alcohol and sodium alginate as aqueous binders for lithium-titanium oxide anode in lithium-ion batteries

Tailoring micro resistance spot welding parameters for joining nickel tab to inner aluminium casing in a cylindrical lithium ion cell and its influence on the electrochemical performance

Graphene sheets have been synthesized from single walled carbon nanohorns by one-step reaction with hydrogen peroxide. The obtained graphene sheets are in pure form and shows good electrical properties. As-synthesized graphene acts as dual function of support as well as reducing agent to prepare graphene-silver nanoparticle composite having uniform particle size of 6 nm. This method can easily be scalable to prepare graphene or graphene supported metal nanoparticle composites for versatile applications.

http://iopscience.iop.org/article/10.1088/2053-1591/aa5ee2/pdf

Vallabha Rao Rikka

Papers

A Novel α‐MoO 3 /Single‐Walled Carbon Nanohorns Composite as High‐Performance Anode Material for Fast‐Charging Lithium‐Ion Battery

In Situ/ex Situ Investigations on the Formation of the Mosaic Solid Electrolyte Interface Layer on Graphite Anode for Lithium-Ion Batteries

Investigation on polyvinyl alcohol and sodium alginate as aqueous binders for lithium-titanium oxide anode in lithium-ion batteries

Tailoring micro resistance spot welding parameters for joining nickel tab to inner aluminium casing in a cylindrical lithium ion cell and its influence on the electrochemical performance

Synthesis of graphene sheets from single walled carbon nanohorns: novel conversion from cone to sheet morphology