No abstract

Recent advances in energy storage technology demand high voltage and high energy density modules at lower cost. Composites of inorganic layered materials with conducting polymers (CPs) are known to exhibit excellent electrical/ electrochemical behavior along with good dimensional stability. Herein, we report on the MoS 2 /polythiophene (PTh) composite as a potential cathode for rechargeable aluminum battery application. Successful composite formation was achieved adopting an in situ chemical oxidative procedure and evaluated employing Fourier transform infrared, X-ray diffraction, thermogravimetry−differential thermal analysis, and field emission scanning electron microscopy coupled with energy-dispersive X-ray analysis. The structural change in the inorganic−organic polymer composite phase and the assessment of the composite displayed a process-dependent exfoliation of the MoS 2 nanosheets which were noticeably different for the synthesized samples coded as MoS 2 /PTh-A and MoS 2 /PTh-B. Both the composites synthesized demonstrate better electrochemical performance than the pristine MoS 2 as the cathode for the aluminum battery, as deciphered through comprehensive cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge−discharge studies. A relatively high discharge capacity of ca. 150 mA h g −1 versus Al/Al 3+ , exhibited for the MoS 2 /PTh composites over multiple cycles, showcases the prospect of these materials. X-ray photoelectron spectroscopy of the composite samples before and post-cycling revealed crucial clues on the nature of composites and their charge−discharge behavior. To sum up, the study opens up the immense possibility of synthesizing and exploring orthodox layered inorganic compounds exfoliated with CPs for next-generation rechargeable battery application.

Lithium-ion batteries have had huge success in the last three decades. Although their chemistry has matured along with commercial acceptance, there is a strong incentive to design battery materials from abundant resources; yet they can deliver high energy and power density with enhanced safety parameters competitively. Magnesium-metal rechargeable batteries remain as one of the potential candidates offering similar chemistry, which might provide an affordable solution. Nevertheless, there are quite a few challenges that restrict their adaptation. One of the major issues is the choice of solvent-based electrolytes that hampers the thermal and electrochemical stability apart from the safety limitations imposed by the volatile and flammable solvents. Herein, we report an unexplored class of electrolytes composed of 1-ethyl-3-methylimidazolium chloride (EMIC) with Mg(ClO4)2 or Mg(CF3SO3)2 based on the class of deep eutectic solvents (DESs) for application in rechargeable magnesium batteries. The optimized molar ratio 1:0.16 and 1:0.14 identified for EMIC-Mg(ClO4)2 and EMIC-Mg(CF3SO3)2 offers appreciably high conductivity, σ25°C of 2.8 and 2.4 mS cm–1, respectively. The anodic stability recorded with graphite as a working electrode was ∼3.0 V vs Mg/Mg2+, and the Graphite|DES|Mg cells were found to deliver ∼40 mAh g–1 over 50 cycles with remarkable stability. Albeit preliminary, the study opens up prospects for designing an alternate class of safe and stable eutectic electrolytes for rechargeable magnesium battery application.