60 mmol/L) 1,3-dioxolane/1,2-dimethoxyethane (DOL/ DME 1/1 vol.%) solution for 24 hours. Afterwards, the resultant polymer was washed with DOL/DME repeated and attached onto the Cu foil and dried overnight at room temperature in the Ar filled glove box before transfer to the beamline chamber for testing. UV-visible Spectroscopy The concentration of lithium sulfide (Li2S6) applied in the UV-vis test is 3 in situ mmol/L, in DOL/ DME (1:1 v/v). 0.5 g of polymer binder was soaked in 3 mmol/L lithium polysulfide in DOL/DME electrolyte in a UV quartz container. A continuous 72 spectra were collected through the Cary 5000 UV-Vis-NIR every 20 minutes during the 24-hour period. Imaging Morphology of the electrode surface is characterized with a JEOL JSM-7500F field emission scanning electron microscope with an accelerating voltage of 15 kV using the high vacuum mode at room temperature. All electrodes are examined in different conditions, including fresh electrode, fully lithiated (in 10th cycle) and fully delithiated (in 10th cycle). The cycled electrodes were disassembled in glove box and flushed with dimethyl carbonate repeated to remove electrolyte residue. The distribution property of polymers is evaluated through both optical observation and Atomic Force Microscopy (AFM) (Agilent Technology 5100). Polymer binder films are coated through doctor blade method on Al foil. The film was air-dried overnight, and vacuum-dried over night before the optical microscopy and AFM study. The polymer film (dry thickness: 5µm) coating was achieved through doctor blade (gap: 50 µm) using a 5 wt% of polymer aqueous solution on Al foil.
60 mmol/L) 1,3-dioxolane/1,2-dimethoxyethane (DOL/ DME 1/1 vol.%) solution for 24 hours. Afterwards, the resultant polymer was washed with DOL/DME repeated and attached onto the Cu foil and dried overnight at room temperature in the Ar filled glove box before transfer to the beamline chamber for testing. UV-visible Spectroscopy The concentration of lithium sulfide (Li2S6) applied in the in situ UV-vis test is 3 mmol/L, in DOL/ DME (1:1 v/v). 0.5 g of polymer binder was soaked in 3 mmol/L lithium polysulfide in DOL/DME electrolyte in a UV quartz container. A continuous 72 spectra were collected through the Cary 5000 UV-Vis-NIR every 20 minutes during the 24-hour period. Imaging Morphology of the electrode surface is characterized with a JEOL JSM-7500F field emission scanning electron microscope with an accelerating voltage of 15 kV using the high vacuum mode at room temperature. All electrodes are examined in different conditions, including fresh electrode, fully lithiated (in 10th cycle) and fully delithiated (in 10th cycle). The cycled electrodes were disassembled in glove box and flushed with dimethyl carbonate repeated to remove electrolyte residue. The distribution property of polymers is evaluated through both optical observation and Atomic Force Microscopy (AFM) (Agilent Technology 5100). Polymer binder films are coated through doctor blade method on Al foil. The film was air-dried overnight, and vacuum-dried over night before the optical microscopy and AFM study. The polymer film (dry thickness: 5µm) coating was achieved through doctor blade (gap: 50 µm) using a 5 wt% of polymer aqueous solution on Al foil.