Shyamal K. Das

Ionic Liquid‐Nanoparticle Hybrid Electrolytes and their Application in Secondary Lithium‐Metal Batteries

Ionic liquid-tethered nanoparticle hybrid electrolytes comprised of silica nanoparticles densely grafted with imidazolium-based ionic liquid chains are shown to retard lithium dendrite growth in rechargeable batteries with metallic lithium anodes. The electrolytes are demonstrated in full cell studies using both high-energy Li/MoS(2) and high-power Li/TiO(2) secondary batteries.

Self-assembled MoS2–carbon nanostructures: influence of nanostructuring and carbon on lithium battery performance

Composites of MoS2 and amorphous carbon are grown and self-assembled into hierarchical nanostructures via a hydrothermal method. Application of the composites as high-energy electrodes for rechargeable lithium-ion batteries is investigated. The critical roles of nanostructuring of MoS2 and carbon composition on lithium-ion battery performance are highlighted.

Sodium–oxygen batteries: a new class of metal–air batteries

Research on sodium–oxygen batteries has gained unprecedented momentum in recent times. With a high theoretical specific energy of 1600 W h kg−1 and an equilibrium discharge potential of 2.3 V, a rechargeable sodium–oxygen battery embodies an attractive new metal–air battery platform for applications in transportation. As an earth-abundant element, sodium has the potential to be a low cost replacement for lithium in electrochemical storage technologies while retaining the majority of its qualities. This highlight focuses on the development and current progress in the field of sodium–oxygen batteries. Strategies for improving the reversibility of the electrode reactions and for understanding and overcoming key problems in sodium–oxygen batteries are also discussed.

In situ synthesis of lithium sulfide–carbon composites as cathode materials for rechargeable lithium batteries

Lithium–sulfur batteries are among the most promising candidates for next-generation rechargeable lithium batteries in view of recent progress on sulfur–carbon composite cathodes. However, further progress on such batteries is hampered by their concomitant need for a metallic lithium anode, which introduces new challenges associated with uneven electrodeposition and lithium dendrite formation. Here we report a method of creating lithium sulfide–carbon composites as cathode materials, which can be paired with high-capacity anodes other than metallic lithium. Lithium sulfide is dispersed in a porous carbon matrix, which serves to improve its electrical conductivity and provides a framework for sequestration of sulfur and lithium polysulfides. The in situ synthesis approach allows facile, scalable synthesis of lithium sulfide–carbon composite materials that exhibit improved electrochemical properties. We also investigate the effect of lithium polysulfides dissolved in the electrolyte on the stability and cycling behavior of Li2S–carbon composite cathodes.

The Li–CO2 battery: a novel method for CO2 capture and utilization

We report a novel primary Li–CO2 battery that consumes pure CO2 gas as its cathode. The battery exhibits a high discharge capacity of around 2500 mA h g−1 at moderate temperatures. At 100 °C the discharge capacity is close to 1000% higher than that at 40 °C, and the temperature dependence is significantly weaker for higher surface area carbon cathodes. Ex-situ FTIR and XRD analyses convincingly show that lithium carbonate (Li2CO3) is the main component of the discharge product. The feasibility of similar primary metal–CO2 batteries based on earth abundant metal anodes, such as Al and Mg, is demonstrated. The metal–CO2 battery platform provides a novel approach for simultaneous capturing of CO2 emissions and producing electrical energy.

High energy lithium–oxygen batteries – transport barriers and thermodynamics

We show that it is possible to achieve higher energy density lithium–oxygen batteries by simultaneously lowering the discharge overpotential and increasing the discharge capacity via thermodynamic variables alone. By assessing the relative effects of temperature and pressure on the cell discharge profiles, we characterize and diagnose the critical roles played by multiple dynamic processes that have hindered implementation of the lithium–oxygen battery.

Aluminium-ion batteries: developments and challenges

The concept of exploring the superior benefits of electropositive metals as anodes in rechargeable metal-batteries has resurfaced in recent times in anticipation of the future societal need for high energy density and affordable batteries. A rechargeable battery based on aluminium chemistry is envisioned to be a low cost energy storage platform, considering that aluminium is the most abundant metal in the Earths crust. The high volumetric capacity of aluminium, which is four and seven times larger than that of lithium and sodium respectively, unarguably has the potential to boost the energy density of aluminium-batteries on a per unit volume basis. Efforts to develop rechargeable aluminium-batteries can be traced to as early as the 1970s, however this area of research has seen a surge in activity since 2010, when the possibility of achieving an ambient temperature aluminium system was convincingly demonstrated. In recent times, rechargeable aluminium-batteries have been rechristened as aluminium-ion batteries. This review aims to comprehensively illustrate the developments regarding rechargeable non-aqueous aluminium-batteries or aluminium-ion batteries. Additionally, the challenges that impede progress in achieving a practical aluminium-ion battery are also discussed.

MoO3 nanoparticle anchored graphene as bifunctional agent for water purification

We report here a facile one step hydrothermal method to anchor MoO3 nanoparticles in graphene. The bifunctionality of graphene-MoO3 nanoparticles is demonstrated via dye adsorption and antibacterial activities. The nanocomposite showed excellent adsorption of methylene blue, a cationic dye, from water compared to pristine MoO3 and graphene. However, it showed negligible adsorption of methyl orange, an anionic dye. Again, the graphene-MoO3 nanoparticles exhibited bacteriostatic property against both Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria.