junyoung mun

Lithium–sulfur batteries (LSBs) have drawn significant attention owing to their high theoretical discharge capacity and energy density. However, the dissolution of long‐chain polysulfides into the electrolyte during the charge and discharge process (“shuttle effect”) results in fast capacity fading and inferior electrochemical performance. In this study, Mn 2 O 3 with an ordered mesoporous structure (OM‐Mn 2 O 3 ) was designed as a cathode host for LSBs via KIT‐6 hard templating, to effectively inhibit the polysulfide shuttle effect. OM‐Mn 2 O 3 offers numerous pores to confine sulfur and tightly anchor the dissolved polysulfides through the combined effects of strong polar–polar interactions, polysulfides, and sulfur chain catenation. The OM‐Mn 2 O 3 /S composite electrode delivered a discharge capacity of 561 mA h g −1 after 250 cycles at 0.5 C owing to the excellent performance of OM‐Mn 2 O 3 . Furthermore, it retained a discharge capacity of 628 mA h g −1 even at a rate of 2 C, which was significantly higher than that of a pristine sulfur electrode (206 mA h g −1 ). These findings provide a prospective strategy for designing cathode materials for high‐performance LSBs.

Deformable lithium‐ion batteries (LIBs) can serve as the main power sources for flexible and wearable electronics owing to their high energy capacity, reliability, and durability. The pivotal role of cathodes in LIB performance necessitates the development of mechanically free‐standing and stretchable cathodes. This study demonstrates a promising strategy to generate deformable cathodes with electrical conductivity by forming 3D interconnected elastomeric networks. Beginning with a physically crosslinked polymer network using poly(vinylidene fluoride‐ co ‐hexafluoropropylene) and 1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]), subsequent exchange with a 1 M LiPF 6 electrolyte imparts elastic characteristics to the cathodes. The resulting LiFePO 4 composite electrodes maintained their resistance under 500 consecutive bending cycles at an extremely small bending radius of 1.8 mm and showed high discharge capacity of 158 mAh g −1 with stable potential plateaus in charging and discharging curves. Moreover, flexible cells utilizing the composite electrodes exhibited superior operational stability under rolling, bending, and folding deformations. image