Selenium/Graphite Platelet Nanofiber Composite for Durable Li–Se Batteries

Abstract

Long-lasting Li−Se cells with a Se/graphite platelet nanofiber (GPNF) composite is prepared for the first time, and it shows a reversible capacity of 489 and 384.7 mAh g Se −1 after 200 and 350 charge/discharge cycles, respectively. It shows superior rate capability and low Se polarization even with a high Se (75 wt %) proportion. It also shows higher capacity and better cycling stability compared to conventional Se/carbon material composites (with graphene oxide (GO), reduced GO, and carbon nanotubes). The effectiveness of GPNFs as a conductive support and for inhibiting the shuttle and dissolution of polyselenides in the electrolyte is also confirmed by conducting atomic force microscopy studies. Nanoscale current maps of Se/GPNFs reveal the presence of homogeneously distributed high-current domains, which are retained even after the first discharge. In contrast, the pristine Se electrode is characterized by predominant low-current regions after the first discharge. The ability of GPNFs to enable the preparation of durable and easily processable Li−Se cells is demonstrated.

Facile Nanostructured Composite Synthesis of Selenium and Molybdenum Chalcogenides/Carbon Nanotubes for Li‐Ion Batteries

“…This result also corresponds to the observation of Se 3p 3/2 in Figure (a) and (b). The binding energies of reduced selenium (Se 2− ) and selenium in zero oxidation state can be compiled as shown in Table S1, which confirms the formation of Se–MC composite and the results were consistent with the obtained XRD and Raman data . Generally, the peak at 59 eV can be assigned to the SeO bonding structures, whereas in the current XPS result, no such characteristic peak was apparently observed at a binding energy of 59 eV, suggesting the nonoccurrence of unreacted SeO 2 .…”

“…Furthermore, selenium and sulfur, which are can be obtained during synthesis process, are also attractive active materials for high‐energy density batteries. Both of these materials have been studied extensively in order to obtain a high capacity battery by the similar approaches of morphology control . Also, selenide and selenium contain a high electron density and has a higher electronic conductivity than sulfide, so it can be expected to enhance performance by improving the electronic conductivity.…”

“…Both of these materials have been studied extensively in order to obtain a high capacity battery by the similar approaches of morphology control. 7,8 Also, selenide and selenium contain a high electron density and has a higher electronic conductivity than sulfide, so it can be expected to enhance performance by improving the electronic conductivity. At the same time, we propose a composite material by also introducing CNTs to improve electron transfer and increase intermaterial connectivity.…”

In Batteria Electrochemical Polymerization to Form a Protective Conducting Layer on Se/C Cathodes for High‐Performance Li–Se Batteries

“…Recently, lithium–selenium (Li–Se) batteries have been considered one of the promising next‐generation batteries not only because they offer a high energy density (2528 Wh L −1 ), which is higher than that of graphite–LiFePO 4 and comparable to that of Li–S batteries, but also because the active material, Se, has a higher electrical conductivity compared with S and LiFePO 4 (10 −3 S m −1 of Se vs 10 −28 S m −1 of S and 10 −7 S m −1 of LiFePO 4 ). [ 5,7,10–26 ] Therefore, a higher utilization of Se in LiBs provides a higher energy density in spite of the lower amount of conductive carbon. [ 12,20–22 ] Moreover, the compatibility of Se with low‐cost carbonate‐based electrolytes reduces costs and mitigates capacity decay, unlike in Li–S batteries where the nucleophilic reaction of carbonyl groups with S degrades the cell performance.…”

Separated Tellurium Nanoparticles Confined in Hollow Polypyrrole for High Performance Li‐Te Cathode

“…Additionally, the electric conductivity of Te (2 × 10 2 S m À 1 ) is much higher than that of S (1 × 10 À 17 S m À 1 ) and Se (1 × 10 À 6 S m À 1 ). [18][19][20] Benefit from these merits, Te will be a prospective electrode material for the LiÀ Te battery. Recently, some researchers have been combined Te with carbonaceous materials to promote the utilization of LiÀ Te batteries.…”