Magnéli phase Ti₄O₇ with high electronic conductivity showed great promise as an inactive component of S cathodes that mitigates some intrinsic limitations of ultra-lightweight lithium-sulfur batteries (LSBs) based on low-cost, high specific capacity and largely environmentally benign sulfur (S). Here we report for the first time a straightforward and economic approach to synthesize mesoporous Magnéli phase Ti₄O₇ microspheres by simply heating a mixture of elemental titanium and TiO₂ in argon. The phase-controlled method utilizes the mildest synthesis conditions to-date with lower temperature and exclusion of flammable hydrogen gas traditionally used, and also avoids generation of exhaust greenhouse gases during carbothermal synthesis using sacrificial polymers. The produced S/Ti₄O₇ composite cathode with 70 wt% S loading efficiently mitigated the shuttle effect by both chemical adsorption and physical trapping of polysulfides. Consequently, this cathode showed high (88%) first cycle columbic efficiency, excellent cycling stability (capacity decay of ~ 0.09% per cycle for 500 cycles), small polarization and good rate performance, significantly exceeding the performance of S/TiO₂ and S/activated carbon cathodes with similar/smaller S loading. We anticipate that this work will provide new avenues for more economic and environmentally friendly synthesis of various Magnéli phase metal oxides, and their exploration in LSBs and other fields.

具有高电导率的Magnéli相Ti ₄ O ₇作为S阴极的惰性成分具有广阔的前景，该活性成分减轻了基于低成本，高比容量和对环境无害的硫的超轻量锂硫电池（LSB）的某些固有局限性（S）。在这里，我们首次报告了一种简单经济的方法，通过简单地加热元素钛和TiO ₂的混合物来合成介孔的Magnéli相Ti ₄ O ₇微球在氩气中。相控方法利用迄今最温和的合成条件，且温度较低，并且排除了传统上使用的可燃气体，并且还避免了在使用牺牲聚合物的碳热合成过程中产生废气排放。所产生的具有70重量％的S负载的S / Ti ₄ O ₇复合阴极通过多硫化物的化学吸附和物理捕获两者有效地减轻了穿梭效应。因此，该阴极显示出高（88％）的第一循环钴效率，出色的循环稳定性（500次循环每循环约0.09％的容量衰减），小的极化和良好的倍率性能，大大超过了S / TiO ₂的性能S / S活性炭阴极具有相似/较小的S负载。我们预计这项工作将为更经济和环境友好的各种Magnéli相金属氧化物的合成及其在LSB和其他领域的探索提供新的途径。