Supplementary Materialssupp info 41598_2019_38728_MOESM1_ESM. against corrosion, and cathode dissolution is usually

Supplementary Materialssupp info 41598_2019_38728_MOESM1_ESM. against corrosion, and cathode dissolution is usually reduced. This graphite-based membrane is usually expected to greatly expedite the deployment of batteries with organic cathodes. Introduction Energy storage technology is a critical research area for the success of portable electronic devices1,2 and electrical transportation3. Such applications need affordable, durable, safe and environmentally friendly battery materials4 with high energy density5. Organic cathode materials are currently promising candidates because they fulfill most of these requirements for an active battery material6. In comparison to inorganic-based cathode materials (such PGE1 cost as LiCoO2 or LiFePO4), organic cathode materials represent a sustainable alternative that does not require energy-intensive transformations7. Furthermore, using organic materials with low molecular weight enhanced the battery PGE1 cost energy because the mass of active material per exchanged electron is usually reduced8C10. Organic cathode materials can also reach high redox potentials, most notably when decorated by electronegative functional groups11. However, they usually suffer from a major limitation, namely their solubility in organic electrolytes12. Even a suprisingly low solubility results in a decreased capability upon bicycling because of the loss of energetic materials. Among organic cathode components, conjugated carbonyl substances have already been intensively scrutinized due to a mix of attractive properties, such as low cost, good theoretical capacity, reversible oxidative behavior, high discharge potential and commercial availability13C16. For example, 3, 4, 9, 10-perylene-tetracarboxylic-dianhydride (PTCDA) is an inexpensive red pigment that is widely investigated as an active material for energy devices (solar cells17, battery18,19). However, Li-PTCDA batteries suffers from poor and irreversible cycling stability due to the dissolution in the electrolyte20. Even more problematic, the dissolved PTCDA migrates through the porous separator and deposits around the anode surface causing irreversible damage21. In order to solve this problem, chemical modifications such as polymerisation22,23, functionalization24,25 and immobilization on carbon materials26,27 have improved cycling stability and coulombic efficiency. However, these altered PGE1 cost cathode materials, which are often prepared by complex processes, contain considerable amounts of inactive mass that cause a decreases of the energy density. Carbon-based membranes are known to suppress polysulfide shuttling behavior leading to enhance the electrochemical overall performance of Rabbit polyclonal to GNRHR lithium-sulfur (Li-S) batteries28C32. Here, we show that carbon materials can also be used as a selective interlayer for Li+ ions in a Li-PTCDA battery to enhance cycle life. For this purpose, we developed a low cost and solvent-free method by applying a thin graphite layer on one side of a commercially available polypropylene (PP) microporous membrane (Celgard 3501, referred here as Celgard). The altered separator, coined as G-separator, acts as a selective layer for the transport of Li+ between electrodes, and protects the lithium anode from corrosion by inhibiting the diffusion of dissolved PTCDA. This graphite interlayer, which adds less than 0.5% to the weight of the battery material, significantly enhances cycling stability with a coulombic efficiency near 100% after 100 cycles. The fabrication of the G-separator does not require any solvent or binder, chemical modification or any energy-consuming curing process. Thus, we envision that this G-separator can be implemented on a large scale, leading to the deployment of lighter, more sustainable batteries. Results and Discussions During the smearing step in the G-separator preparation, the physical friction results in the formation of a continuous PGE1 cost PGE1 cost and non-porous film of graphite (Fig.?1a) that does not affect the original flexibility of Celgard (Supplementary Fig.?1). Scanning electron microscopy (SEM) of a G-separator shows that the graphite interlayer (Fig.?1b) is clean, uniform in thickness, devoid of cracks or aggregates and it completely covers the porous morphology of the Celgard (Fig.?1c).The thickness of the graphite layer is dependant of the smearing time (see supporting information). The dense layers of graphite have the average thicknesses of 360??50?nm (Fig.?1d) and 640??70?nm (Fig.?1e), which match yet another mass of 2% and 4% for the membrane (0.25 and 0.5%, respectively, in accordance with the battery mass). The scotch tape check qualitatively verified that graphite provides great physical adhesion towards the substrate. Raman spectroscopy demonstrated that the finish process led to a higher percentage of edge flaws, as indicated by an increased ratio Identification/IG (Supplementary Fig.?2)33. Such behavior is certainly expected as the mechanised drawing procedure causes a misalignment from the graphite.