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Limitations of capacitive deionization (CDI) and future commercialization efforts are intrinsically bound to electrode stability. In this work, thermal treatments are explored to understand their ability to regenerate aged CDI electrodes. We demonstrate that a relatively low thermal treatment temperature of ∼500 °C can sufficiently recover the lost salt adsorption capacity of degraded electrodes. Furthermore, a systematic study of electrode replacement clarifies that the desalination ability loss and regeneration for a CDI cell are isolated to the aged anode, as expected. Characterizations of surface functionalities support that the acidic oxygen-containing functional groups formed in situ during cycling undergo thermal decomposition during treatment. The modified Donnan model quantitatively confirms that the surface charges originate from the formation/decomposition of functional groups. Accordingly, the lost pore volume and the increased resistance are recovered during thermal treatments, while the surface morphologies and pore structure of the electrodes are well-preserved. Therefore, thermal treatment can be applied practically to extend the lifetime of aged electrodes. This study also offers insights into strategies for minimizing electrode degradation or in situ regeneration such that the technology gains momentum for future commercialization.

Among elemental semiconductors, tellurium (Te) exhibits unique mechanical and electromechanical properties due to its highly anisotropic crystal structure and mixed interatomic bonding modes. A lack of experimental investigations of these properties inhibits its adoption in new applications both in bulk form as well as at the nanoscale. In this study, uniaxial tensile tests were conducted in a scanning electron microscope (SEM) on [0001] orientated Te nanowires (NWs) with diameters ranging from 15 to 35 nm. An average elastic modulus is estimated to be 38.6 ± 4.7 GPa. Both elastic and elastic–plastic behaviors are observed in tested NWs, with a large fracture strain of up to 18% achieved in the latter case. Regardless of the deformation type, electromechanical tests of Te NWs show a trend of decreasing resistance with increasing strain at low-to-moderate tensile strains (0–4%). This piezoresistive effect provides for new opportunities for tellurium to be utilized either in nanoscale devices or in systems that can utilize the extraordinary properties of single-crystal tellurium.