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Li and 33 S solid-state magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy were used to identify the discharge products in lithium-sulfur (Li-S) battery cathodes. Cathodes were stopped at different potentials throughout battery discharge and measured ex-situ to obtain chemical shifts and T 2 relaxation times of the products formed. The chemical shifts in the spectra of both 6 Li and 33 S NMR demonstrate that long-chain, soluble lithium polysulfide species formed at the beginning of discharge are indistinguishable from each other (similar chemical shifts), while short-chain, insoluble polysulfide species that form at the end of discharge (presumably Li 2 S 2 and Li 2 S) have a different chemical shift, thus distinguishing them from the soluble long-chain products. T 2 relaxation measurements of discharged cathodes were also performed which resulted in two groupings of T 2 times that follow a trend and support the previous conclusions that long-chain polysulfide species are converted to shorter chain species during discharge. Through the complementary techniques of 1-D 6 Li and 33 S solid-state MAS NMR spectroscopy, solution 7 Li and 1 H NMR spectroscopy, and T 2 measurements, structural information about the discharge products of Li-S batteries is obtained.

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