Evaluating the Effect of Binder for Sulfurized Polyacrylonitrile Cathode via Optical Fiber Sensors

Abstract

Sulfurized polyacrylonitrile (SPAN) is a very stable and promising sulfur‐based cathode material for high energy density lithium–sulfur (Li–S) batteries, which can circumvent the polysulfides dissolution issue. However, the stress concentration caused by volume change in SPAN cathodes is relatively significant but is rarely focused on. It is widely reckoned that the binder plays a key role in buffering the stress induced by electrode materials and hence maintains the integrity of electrodes. Nevertheless, the understanding of the actual effect of binders to SPAN cathodes from the aspect of mechanics remains to be deepened. Here, the optical fiber Bragg grating (FBG) is implanted into SPAN cathode films to in situ evaluate the electrochemo‐mechanical behaviors by using four different binders. The internal strain evolution of SPAN cathodes is affected by multiple factors of adhesion and mechanical properties of different binders. It is found that the SPAN cathode using poly(acrylic acid) (PAA) binder with outstanding mechanical properties experiences the largest strain change but the electrochemical performance is even better under high sulfur loading. Furthermore, the strain evolution is monitored under high sulfur loading condition and how the sulfur loading affects the signals of the built‐in FBG sensors is tried to figure out.

Stabilizing Zn2SiO4 Anode by a Lithium Polyacrylate Binder for Highly Reversible Lithium-Ion Storage

“…After the structural features and morphologies were firmly demonstrated, the electrochemical properties of Zn 2 SiO 4 @C were evaluated using a series of binders. As shown in Figure S10, the binders PVDF, CMC/SBR, LA133, and LiPAA were selected due to their distinct functional groups, which alter interactions with other electrode components, enhance the adhesion properties of the electrodes, and provide electrochemical stability during cycling. ,− Initially, the electrochemical performance of Zn 2 SiO 4 @C using different binders in the first cycle was carefully evaluated. As shown in Figure a, the discharge/charge capacity and initial Coulombic efficiency (ICE) of the electrodes utilizing various binders during the first cycle were summarized.…”