Lithium‐sulfur battery suffers from sluggish kinetics at low temperatures, resulting in serious polarization and reduced capacity. Here, this work introduces medium‐entropy‐alloy FeCoNi as catalysts and carbon nanofibers (CNFs) as hosts. FeCoNi nanoparticles are in suit synthesized in cotton‐derived CNFs. FeCoNi with atomic‐level mixing of each element can effectively modulate lithium polysulfides (LiPSs), multiple components making them promising to catalyze more LiPSs species. The higher configurational entropy endows FeCoNi@CNFs with extraordinary electrochemical activity, corrosion resistance, and mechanical properties. The fractal structure of CNFs provides a large specific surface area, leaving room for volume expansion and Li2S accumulation, facilitating electrolyte wetting. The unique 3D conductive network structure can suppress the shuttle effect by physicochemical adsorption of LiPSs. This work systematically evaluates the performance of the obtained Li2S6/FeCoNi@CNFs electrode. The initial discharge capacity of Li2S6/FeCoNi@CNFs reaches 1670.8 mAh g−1 at 0.1 C under ‐20 °C. After 100 cycles at 0.2 C, the capacity decreases from 1462.3 to 1250.1 mAh g−1. Notably, even under ‐40 °C at 0.1 C, the initial discharge capacity of Li2S6/FeCoNi@CNFs still reaches 1202.8 mAh g−1. After 100 cycles at 0.2 C, the capacity retention rate is 50%. This work has important implications for the development of low‐temperature Li‐S batteries.

Newly designed all-electrochem-active thick electrode (∼500 μm) with dual-continuous integrated skeletons of defective rutile-anatase TiO 2 (D-R-A-TiO 2 ) heterojunctions and carbon have been introduced to enhance efficient electron− ion transport for high-rate energy storage, which provides a new idea for low-temperature lithium storage. For the first time, we anneal anatase TiO 2 integrated carbon under CO 2 atmosphere for converting anatase to rutile and activating carbon simultaneously, to fabricate freestanding all-electrochem-active thick electrode. The D-R-A-TiO 2 heterojunctions contain a type II staggered band alignment, which significantly induce highly localized electrons and lower the migration barrier of ions. The continuous D-R-A-TiO 2 heterojunctions form synergistically advantageous electronic networks, and the thick electrode (up to 60.97 mg cm −2 ) delivers outstanding areal capacity (14.14 mAh cm −2 at 0.61 mA cm −2 ) under 30 °C. The areal capacity is 8.62 mAh cm −2 at 0.57 mA cm −2 under −10 °C. When the temperature drops to −20 °C, the areal capacity still delivers 4.92 mAh cm −2 at 0.57 mA cm −2 . And the D-R-A-TiO 2 electrode still delivers 3.2 mAh cm −2 capacity after 70 cycles at 0.57 mA cm −2 under −20 °C.

Lithium-ion batteries (LIBs) have been extensively employed in a range of electrical vehicles and portable devices in virtue of their high energy density and stable cycle life. However, poor performance under low temperatures hinders their application in cold climates and regions. Herein, single-shell (carbon) multiple-core (ultra-small MnO@C nanoparticles) hollow carbon nanospheres (MnO@C@HCS) were prepared by a sacrificial template method, and MnO@C@HCS showed excellent low-temperature electrochemical performance. These MnO@C cores with large surface areas can shorten diffusion lengths of lithium ions and enhance diffusion rates along their rich grain boundaries, enabling rapid charging/discharging. The hollow carbon nanosphere with a porous shell can block serious agglomeration of nanoparticles and regulate the amount of electrolyte filled in the hollow nanosphere to reduce side reactions between highly active electrode materials and electrolytes. The hollow structure formed between the core and the shell mitigates the volume expansion and contraction during cycling. The MnO@C@HCS anode exhibits high specific capacities (1027 mAh g −1 at 0.20 A g −1 ) and high rate performance (353 mAh g −1 at 10.00 A g −1 ) under room temperature. Furthermore, the MnO@C@HCS anode maintains a satisfactory discharge capacity under low temperatures (461 mAh g −1 at 0.05 A g −1 under −10 °C, 220 mAh g −1 at 0.10 A g −1 under −20 °C, respectively). The contribution of pseudocapacitance to the capacity decreases as the test temperature drops. Our strategy provides a design concept for the high-performance anode for low-temperature lithium storage.