ChemElectroChem (May 2025)
Understanding and Comparing the Stability of Water‐ versus NMP‐Based Tin(IV)Sulfide Electrodes Using Post‐Mortem Analysis
Abstract
Abstract Tin (IV) sulfide (SnS2) is a promising anode material for Li‐ion batteries (LIBs) due to its high practical reversible capacity of 623 mAhg−1. However, its cycling stability is relatively poor and its long‐term degradation during cycling is not yet thoroughly investigated. In this work, a post‐mortem analysis of SnS2 electrodes was performed at pristine state, after the 1st cycle and at 80 % state‐of‐health. The analysis compared water‐based (Na‐CMC/SBR) and NMP‐based (PVDF) electrodes revealing insights into their degradation mechanisms and electrochemical performance. During the first cycle, SnS2 converts into Sn and Li2S identified by XRD, causing particle cracking and exfoliation. XPS and Raman spectroscopy identified Sn, SnFx, LiF, Li2S and carbonates species forming the solid electrolyte interphase (SEI), while in‐situ dilatometry revealed up to 60 % irreversible expansion after the first cycle. These species are also found after at 80 % SOH along with an increase in fluorine species, SEI thickness and interfacial resistance. Water‐based electrodes exhibited better cycling stability, with 80 wt.% SnS2 and 10 wt.% binder retaining 80 % capacity after 180+ cycles. These findings underscore the critical role of binder choice and processing in enhancing SnS2 anodes’ durability and capacity retention, paving the way for sustainable, high‐performance LIB anodes.
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