To effectively restrain the dissolution of soluble polysulfides and fully utilize the active sulfur materials in lithium-sulfur (Li-S) batteries, host materials with unique compositions and porous structures have been pursued. Herein, we have investigated the mechanism of the excellent activity of oxygenated g-C₃N₄ for Li-S batteries from theoretical perspective, and the further experiment confirms that our O-g-C₃N₄-S cathode exhibits much better electrochemical performance compared with those in previous reports. Our DFT calculations reveal that the oxygenated material has better electrical conductivity and stronger adsorption ability with the Li₂S_x species compared with the pristine g-C₃N₄ and other two-dimensional (2D) materials. Furthermore, we have confirmed experimentally that the O-g-C₃N₄-S composite cathode exhibits excellent electrochemical performance in Li-S batteries with high reversible discharge capacity of 1030 mAh g⁻¹ after 100 cycles at 0.2 C, great rate capability with the discharge capacity of 364 mAh g⁻¹ even at 5.0 C, and outstanding long-term cyclic stability with the discharge capacity of 465 mAh g⁻¹ after 1000 cycles at 1.0 C (capacity decay was only 0.046% per cycle). Our results also suggest that theoretical study will play a significant role in predicting and screening novel materials with better performance.

为了有效地抑制可溶性多硫化物的溶解并充分利用锂硫（Li-S）电池中的活性硫材料，人们一直在寻求具有独特组成和多孔结构的主体材料。在这里，我们从理论的角度研究了充氧的gC ₃ N ₄对Li-S电池的优异活性的机理，进一步的实验证实，我们的OgC ₃ N ₄ -S阴极与以前相比具有更好的电化学性能。报告。我们的DFT计算表明，含Li ₂ S _x的含氧材料具有更好的电导率和更强的吸附能力。与原始gC ₃ N ₄和其他二维（2D）材料相比。此外，我们已经通过实验证实，OgC ₃ N ₄ -S复合阴极在Li-S电池中表现出优异的电化学性能，在0.2 C循环100次后具有1030 mAh g ^-1的高可逆放电容量，具有极高的倍率放电容量即使在5.0 C时也能达到364 mAh g ^-1的电量，并具有出色的长期循环稳定性，放电容量为465 mAh g ^-1在1.0 C下进行1000次循环后（每个循环的容量衰减仅为0.046％）。我们的结果还表明，理论研究将在预测和筛选性能更好的新型材料方面发挥重要作用。