Electronic waste management is one of the key challenges for the green revolution without affecting the environment. The wide use of printer devices has brought a horde of discarded waste toner, which release ∼6000 tons of processed carbon powder into the atmosphere every year that would essentially pollute the atmosphere. Here, we propose a one-step thermal conversion of waste toner powder into carbon/Fe3O4 nanocomposites for energy storage applications. Recovered toner carbon (RTC) and toner carbon calcined at 300 °C (RTC-300) were characterized using various analytical tools. From the FE-SEM analysis, the presence of carbon particles with uniformly decorated Fe3O4 nanoparticles was confirmed. RTC-300 carbon was used as an electrode material for supercapacitors, and it exhibited a high specific capacitance of 536 F/g at a current density of 3 A/g, which is almost six times higher than that of the commercial mesoporous graphitized carbon black. RTC-300 showed excellent electrochemical stability of 97% over 5000 cycles at a high current density of 20 A/g. The fabricated symmetric cell using RTC-300 electrode materials in an aqueous electrolyte with a cell voltage of 1.8 V delivered a high energy and high-power density of 42 W h/kg and 14.5 kW/kg, respectively. The fabricated device is stable up to 20,000 cycles at a high current density of 20 A/g with a loss of 23% capacitance.

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Lithium titanate (Li4Ti5O12) is a commercial anode material used for high-power and long-lifespan lithium batteries. The key drawback of this material is its low electronic conductivity. Although doping is commonly used to solve this problem, the introduction of dopants also diminished lattice stability. In this work, we studied fast and slow laser-induced degradation processes of single Mn-doped lithium titanate particles and proposed a physicochemical model of their degradation mechanism. We suppose that the preferable route of LTO alteration is the formation of amorphous phases rather than crystalline decomposition products. Our results may be useful for not only developing a nondestructive characterization tool utilizing Raman spectroscopy but also for understanding other degradation processes, including thermal alteration and structural changes caused by the intercalation/deintercalation cycles of lithium ions.

Lithium-ion batteries (LIBs) have become vital energy-storage devices in electric vehicles (EVs). Li 4 Ti 5 O 12 (LTO) is a promising material of LIB because of its high rate capability, cyclability, and safety compared to the graphite-based anode materials in commercial LIBs. However, one of the major concerns in LTObased LIBs is gassing, which results from the interfacial reaction between LTO and organic electrolyte solutions, unlike the reduction decomposition of an electrolyte in graphite electrodes. Carbon coating on LTO has been proposed to mitigate the gassing by preventing such side reactions, even though reports have been conflicting. In this work, there are different kinds of carbon-coated LTO deposited using the thermal decomposition of ethanol that has been investigated at elevated temperature using In Operando pressure analysis to answer the paradox of the effect of carbon coating on the gassing behavior on LTO. Our Spatial Raman Spectroscopy Analysis (SRS) shows that the carbon coating coverage is likely responsible for the discrepancy in the gassing behavior reported by other studies. Our proposed deposition process achieves complete coverage with an ultrathin 3 nm carbon coating layer which mitigates the interfacial reactions while improving electrochemical performance.

The Cover Feature illustrates the importance of carbon coating coverage on gassing behavior of lithium titanate based lithium‐ion batteries since safety is one of the major concerns down the road as we are moving towards a sustainable future. More information can be found in the Research Article by K. Govindarajan, R. N. Nasara and S.‐k. Lin.