Stabilization of Li-Se Batteries by Wearing PAN Protective Clothing

Sustainable ZIF-67/Mo-MXene-Derived Nanoarchitecture Synthesis: An Enhanced Durable Performance of Lithium-Selenium Batteries

Selenium-based electrodes have garnered attention for their high electrical conductivity, compatibility with carbonate electrolytes, and volumetric capacity comparable to sulfur electrodes. However, real-time application is hindered by rapid capacity deterioration from the "shuttle effect" of polyselenides and volume fluctuations. To address these challenges, a hybrid Se@ZIF-67/Mo-MXene-derived (Se@Co-NC/Mo2C) nanoarchitecture is developed via an economically viable in situ electrostatic self-assembly of ZIF-67 and Mo2C nanosheets. The catalytic effects and porous framework of Co-NC/Mo2C enhance electrode attributes, promoting superior adsorption and conversion of lithium polyselenides and facile ion/electron transport within the electrode, resulting in stable electrochemical performance. Lithium-selenium batteries (LSeBs) exhibit remarkable characteristics, boasting high specific capacity and exceptional durability. The Se@Co-NC/Mo2C electrode delivers a reversible capacity of 503.5 mAh g-1 at 0.5 C with 98% capacity retention, 100% Coulombic efficiency, and exceptional cyclic durability through 8600 cycles. In sustainability tests at 10C/1C charging/discharging, the Se@Co-NC/Mo2C electrode demonstrates an optimistic and stable capacity of ≈370.6 mAh g-1 with 93% capacity retention at the 3100th cycle in a carbonate-based electrolyte and ≈181.3 mAh g-1 with 92% capacity retention after 5000 cycles in an ether-based electrolyte, indicating exceptional stability for practical rechargeable batteries. This cost-effective and efficient approach holds significant potential for high-performance and durable LSeBs.

High-Rate Lithium-Selenium Batteries Boosted by a Multifunctional Janus Separator Over a Wide Temperature Range of -30 °C to 60 °C

Lithium-selenium batteries are characterized by high volumetric capacity comparable to Li-S batteries, while ≈1025 times higher electrical conductivity of Se than S is favorable for high-rate capability. However, they also suffer from the "shuttling effect" of lithium polyselenides (LPSes) and Li dendrite growth. Herein, a multifunctional Janus separator is designed by coating hierarchical nitrogen-doped carbon nanocages (hNCNC) and AlN nanowires on two sides of commercial polypropylene (PP) separator to overcome these hindrances. At room temperature, the Li-Se batteries with the Janus separator exhibit an unprecedented high-rate capability (331 mAh g-1 at 25 C) and retain a high capacity of 408 mAh g-1 at 3 C after 500 cycles. Moreover, the high retained capacities are achieved over a wide temperature range from -30 °C to 60 °C, showing the potential application under extreme environments. The excellent performances result from the "1+1>2" synergism of suppressed LPSes shuttling by chemisorption and electrocatalysis of hNCNC on the cathode side and suppressed Li-dendrite growth by thermally conductive AlN-network on the anode side, which can be well understood by the "Bucket Effect". This Janus separator provides a general strategy to develop high-performance lithium-chalcogen (Se, S, SeS2 ) batteries.

Recent Advancements in Selenium-Based Cathode Materials for Lithium Batteries: A Mini-Review

Selenium (Se)-based cathode materials have garnered considerable interest for lithium-ion batteries due to their numerous advantages, including low cost, high volumetric capacity (3268 mAh cm−3), high density (4.82 g cm−3), ability to be cycled to high voltage (4.2 V) without failure, and environmental friendliness. However, they have low electrical conductivity, low coulombic efficiency, and polyselenide solubility in electrolytes (shuttle effect). These factors have an adverse effect on the electrochemical performance of Li-Se batteries, rendering them unsuitable for real-world use. In this study, we briefly examined numerous approaches to overcoming these obstacles, including selecting an adequate electrolyte, the composition of Se with carbonaceous materials, and the usage of metal selenide base electrodes. Furthermore, we examined the effect of introducing interlayers between the cathode and the separator. Finally, the remaining hurdles and potential study prospects in this expanding field are proposed to inspire further insightful work.