The synergistic adsorption-electrocatalysis research of Mn2P interlayer for durable large-capacity and high-energy-efficiency Li-S batteries

• Synergistic adsorption-electrocatalysis effectively suppresses the shuttle effect. • Mn 2 P@C helps to improve the solid–solid and solid–liquid phase transformation kinetics of LiPSs. • Mn 2 P@C can effectively reduce the internal resistance of Li 2 S nucleation growth and activation process. The commercialization of Li-S batteries (LSBs) as next-generation high-energy–density energy storage devices is hindered by the remarkable shuttle effect of soluble lithium polysulfides (LiPSs). In this study, Mn 2 P-based materials (Mn 2 P@C) were investigated as an interlayer between S-contained cathode and separator to confine S species in the cathode region. Specifically, the porous structure of amorphous carbon layer has a physical adsorption effect on LiPSs, while Mn 2 P not only exhibits a strong chemical bonding force with LiPSs but also helps enhance the solid–liquid phase conversion and Li 2 S nucleation growth kinetics. Benefiting from the desirable modulation of Mn 2 P@C, the LSBs have good cycling stability (0.04% capacity decay per cycle), favorable rate capability (659.7 mAh g −1 at 5C), and high energy efficiency (81.4% at 5C). The LSBs still show a specific capacity of 490 mAh g −1 even with a high S loading (8.6 mg cm −2 ) and lean electrolyte (E/S = 6.2 μL mg −1 ). Furthermore, the LSBs with Mn 2 P@C exhibited high resistance to self-discharge. This study shows Mn 2 P@C’s great potential in the field of LSBs with high energy density and efficiency and provides some insights into commercial design and other relevant fields.