Herein, the synthesis of a novel lithium sulfide (Li2S)‐based material is presented. The material is composed of Li2S and lithium sulfenamide, which are formed in and coprecipitated from an ethylenediamine solution as an amorphous, but solid compound. The sulfenamide compound is shown to be an effective carbon source to obtain carbon‐coated Li2S via post‐processing. Both the pristine and carbon‐coated materials are characterized by a series of physicochemical methods and preliminarily investigated for application in batteries. The pristine material possesses a remarkably low activation potential. This ease of activation is particularly beneficial for solid‐state cells, where the material shows a much better performance than the commercially available Li2S.

In this work, the stability of ether-based electrolytes for Li-S batteries is investigated with particular regard to the effect of dissolved oxygen. Specifically, the performance of two different electrolyte solvents, i.e., 1,2-dimethoxyethane and its mixture with 1,3-dioxolane (DME:DOL, 1:1 v/v), is characterized in cells assembled in dry air environment, which would substantially lower production costs with respect to inert atmosphere (Ar). Although stability of all the components would suggest that Li-S batteries built in both the environments should behave similarly, it is found that cells containing the DME:DOL-based electrolyte are rather unstable in the presence of O 2 in contrast to those employing DME-based electrolyte, which show a relatively good performance. The different sensitivity toward O 2 of these electrolytes is associated to the ring-opening reaction of DOL, which happens to a greater extent when O 2 is present, but occurs also in its absence. Based on these results a mechanism for electrolyte degradation in Li-S cells, and its reaction with dissolved polysulfides is proposed, which rationally explain for the first time the behavior already reported in literature for these kind of batteries. These findings are also relevant to the field of Li-O 2 batteries, where these ether-based electrolytes are also used. Sulfur has been extensively investigated as a new cathode material for secondary batteries, in order to replace metal oxides normally used in lithium-ion batteries (LIBs). The first point of interest is its high theoretical specific capacity, around 1672 mAh g −1 , but, as a raw material sulfur is also non-toxic, readily available, and very inexpensive. It is indeed one of the main side products of crude oil refining, with more than 60 million tons produced annually.1 Even the relatively low operating voltage of sulfur-based cathodes, at around 2 V vs. Li/Li + , can be considered as a potential advantage, making it intrinsically safer. 2 Furthermore, the high specific gravimetric capacity of sulfur enables the remarkable specific energy of about 2600 W h kg −1 . However, Lithium-Sulfur batteries (LSB) still present some specific challenges that need to be solved to enable their commercialization.2 First, sulfur has a very low electrical conductivity, around 5 × 10 −30 S cmat 25• C, requiring the introduction of a conductive matrix, normally carbon-based. The carbon host is generally electrochemically inert, such that it decreases the energy density of the electrode as whole, especially since it is often near to 50 wt% of the total sulfur-composite mass. Secondly, and most importantly, sulfur is a conversion material undergoing several chemical transformations during discharge and forming a variety of different polysulfides with the formal oxidation state of sulfur changing from 0 to −2. Some of these intermediate species are soluble in the electrolyte, and very reactive toward both the electrolyte itself 3,4 and the lithium metal anode. 2,5 Most importantly though, their dissolution cause...

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The development of high‐performing materials that, at the same time, can be synthesized from cheap precursors, such as biowaste, is of critical importance for the realization of advanced and sustainable electrochemical double layer capacitors (EDLCs). Herein, reported for the first time, the use of casein extracted from expired milk for the realization of activated carbon (AC), suitable for EDLCs, is proposed. Utilizing this abundant and cheap precursor it is possible to obtain microporous AC that, in organic electrolytes (conventional and non), displays capacitance value comparable with those of commercially available ACs.