No abstract

In the fast-developing world, people must migrate to hybrid electric vehicles with a high energy density of lithium-ion batteries to reduce air and sound pollution primarily. Herein, acid hydrolysis is used to depolymerize vest post-consumer polyethylene terephthalate (PET) bottles, resulting in pure terephthalic acid (TPA). It was used in an acid-base reaction to produce the dilithium terephthalate (Li 2 TP). By using 1 H, 13 CNMR, and FTIR spectroscopy, the obtained TPA and its salt Li 2 TP are thoroughly studied. In terms of electrochemical properties, TPA has a restricted reversible capacity of 102 mAh g À 1 with dramatic fading and a coulombic efficiency of 98.2 % over the 50th cycle at 1 C. The resulting Li 2 TP, displays a three-fold higher reversible capacity of 295 mAh g À 1 , with 99.8 % capacity retention and stable cycling at a similar rate over the 50th cycle. Moreover, computationally found that the charged state of Li 2 TP has a highly unstable structure due to a high steric hindrance and strong similar charge repulsion between lithium ions and it shows bandgap energy 0.2318 eV with four ionic bonds (1.7748 Å) and two new metallic bonds (3.2114 Å), which is 22 times smaller than TPA. Furthermore, Li 2 TP has a lower dielectric constant/loss and higher dipole movement than TPA, with values of 1.32E + 04/1.24E + 03, and 5.93E + 03 respectively, and it improves Li-ion transportation of Li 2 TP in organic electrolytes.

Despite lithium-ion battery (LIB) and supercapacitor materials have gone through numerous enhancements, achieving high energy density as well as power density together is still a dream for the industries. In this scenario, herein we report, boric acid coated αÀ MnO 2 anode with 1288 mAh g À 1 at 0.1 C at the initial cycle and of an average discharge capacity of 570 mAh g À 1 at 0.1 C over 20 cycles, high-rate capability and 100 % Coulombic efficiency after 60 cycles for LIB. The Li + diffusion coefficient estimated from GITT and EIS measurements reveals that the H 3 BO 3 coated αÀ MnO 2 electrode has superior Li-ion kinetics ( D Li þ ~10 À 10 cm 2 s À 1 ) than bare αÀ MnO 2 . Coin cells with boric acid coated αÀ MnO 2 electrode are able to power up red and blue LEDs continuously for about 24-32 hours. The ex-situ investigations reveal an interesting self-assembled active electrodeelectrolyte interfacial bridging Li 4 B 2 O 5 layer formation. This significant active layer allows free migration of lithium ions across interface that leads to good cyclability. In flexible supercapacitor, the boric acid coated αÀ MnO 2 yields excellent cyclability over 500 cycles with specific capacitance of 35 F g À 1 at 1 A g À 1 and further 200 cycles at 30°acute angle with 21 F g À 1 at 1 A g À 1 . The research overthrows the significance of boric acid in conversion reactions for active interfacial bridging layer in LIB and hydroxyl ion capturing agent in flexible supercapacitor.

Li-ion battery cathodes appear to be a significant factor affecting the total amount of energy delivered and the cost of the battery systems. LiVXO4F (X = B, Si), a polyanionic-based tavorite structure, is investigated as a cathode for Li-ion batteries and its capability to endure in sensitive mode operations, i.e., at temperatures of approximately 55 and −10 °C. Due to the near-freezing point at the atomic level and the absence of kinetic energy, a battery system operating at a lower temperature is theoretically expected to perform inferior. On the contrary, Vanadium boron oxyfluoride (VBF) has better electrochemical properties because of its tightly packed covalent bond, which produced structural stability at low temperature activities. This intriguing feature appears to hold promise for its use in advanced rechargeable battery systems in low-temperature areas and cold storage devices. This might pave the path for future energy storage and conversion devices to use neoteric tavorite structured electrodes.