Dense MoS2 Micro‐Flowers Planting on Biomass‐Derived Carbon Fiber Network for Multifunctional Sulfur Cathodes

The significant challenge in lithium‐sulfur batteries (LSBs) arises from low conductivity of sulfur cathode, loss of active sulfur species due to less anchoring sites and sluggish redox kinetics of lithium polysulfides (LPSs). Herein, the dense MoS2 micro‐flowers assembled by cross‐linked 2D MoS2 nanoflakes planting on biomass‐derived carbon fiber (CF) network (MoS2/CFs) are fabricated as multifunctional sulfur cathodes of LSBs. The 2D MoS2 nanoflakes supported on CF provide abundant anchoring sites for strong adsorption, while the 3D flowerlike structure prevents lamellar aggregation of 2D MoS2 nanoflakes. Importantly, the dense MoS2 micro‐flowers planting on the network weaved by biomass‐derived CFs ensures the high electronic conductivity of the MoS2/CFs composite, sufficient electrode/electrolyte interaction, fast electron and Li+ transportation. Moreover, the CF network weaved from cost‐effective tissue paper reduces the cost of LSBs. Thus, the S‐MoS2/CFs cathode exhibits a high rate capability (1149 and 608 mA h g−1 are obtained at 0.2 C and 4 C, respectively), excellent cyclic performance with ∼75% capacity retention and 99% Coulombic efficiency at 2 C after 500 cycles, corresponding to ∼0.05% capacity fading per cycle only, as well as structure integrity during the discharge/charge process.800 Dong Chuan Road, Minhang District, Shanghai 200240, ChinaA novel, cost‐effective, dense 3 D MoS2 micro‐flowers assembled by cross‐linked 2D MoS2 nanoflakes planting on biomass‐derived carbon fiber (CF) network (MoS2/CFs) are fabricated as multifunctional sulfur cathodes of LSBs. The 2D MoS2 nanoflakes provide abundant anchoring sites for strong adsorption, while the 3D flowerlike structure prevents lamellar aggregation of 2D MoS2 nanoflakes. Significantly, the dense MoS2 micro‐flowers supported on carbon fibers ensures the high electronic conductivity of the MoS2/CFs composite, sufficient electrode/electrolyte interaction, fast electron and Li+ transportation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155938/1/slct202001729-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155938/2/slct202001729_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155938/3/slct202001729.pd

Electrocatalytic conversion of lithium polysulfides by highly dispersed ultrafine Mo2C nanoparticles on hollow N‐doped carbon flowers for Li‐S batteries

The significant challenge in exploring novel nanostructured sulfur host materials for Li‐S batteries is to simultaneously mitigate the notorious shuttle effect and catalytically enhance the redox kinetics of lithium polysulfides (LPSs). Herein, a novel ultrafine Mo2C nanoparticles uniformly distributed on 2D nanosheet‐assembled 3D hollow nitrogen‐doped carbon flowers (HNCFs) is designed. The Mo2C/HNCFs architecture with unique flower‐like morphologies not only efficiently suppressed the aggregation of 2D nanosheets but also highly distributed the ultrafine Mo2C nanoparticles that act as catalytic active sites for efficient adsorption and conversion of LPSs. Furthermore, the 3D hierarchical arrangement can afford ample internal space to accommodate sulfur species, large volume expansion, 3D electron pathway, and physical/chemical blockage of LPSs to reduce the loss of active materials. The Mo2C/HNCFs composite exhibits a high rate capability, unprecedented capacity retention of 92% over 100 cycles at 0.5 C placing Mo2C/HNCFs one of the best LPSs adsorbents and electrocatalysts.Ultrafine Mo2C nanoparticles on hollow N‐doped carbon flowers have been employed as efficient catalytic active sites for conversion of LPSs, which can not only enhance the LPSs‐adsorption ability but also accelerate the redox kinetics of polysulfide conversion. Besides, the unique architecture of 2D nanosheets assembled 3D hollow N‐doped carbon flowers contributes to Li+ transportation and electrolyte infiltration.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155989/1/eom212020.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155989/2/eom212020_am.pd

Cathode materials for rechargeable aluminum batteries : current status and progress

This work was financially supported by the National Natural Science Foundation of China (No. 21477046, 21277060 and 51361130151), Key Technology R&D Program of Shandong Province (No. 2016ZDJS11A03), Science Development Project of Shandong Province (No. 2014GGX104004) and Natural Science Foundation of Shandong Province (No. ZR2015EM044).Peer reviewedPostprin

Practical energy densities, cost, and technical challenges for magnesium- sulfur batteries

Amid burgeoning environmental concerns, electrochemical energy storage has rapidly gained momentum. Among the contenders in the - beyond lithium- energy storage arena, the magnesium- sulfur (Mg/S) battery has emerged as particularly promising, owing to its high theoretical energy density. However, the gap between fundamental research and practical application is still hindering the commercialization of Mg/S batteries. Here, through reviewing the recent developments of Mg/S batteries technologies, especially with respect to energy density and cost, we present the primary technical challenges on both materials and device level to surpass the energy density and cost- effectiveness of lithium- ion battery. While the high electrolyte- sulfur ratio and the expensive liquid electrolyte are significantly limiting the practical application of Mg/S batteries, we found that solid- state Mg electrolyte appears to be a feasible solution on the basis of energy density and cost evaluation.Rechargeable magnesium- sulfur (Mg/S) batteries represent one of the most attractive electrochemical systems, in terms of energy density, safety, and cost. We summarize the current status of Mg/S batteries in view of materials development, and comparative study of current literature. We also systematically investigate the relationships between the gravimetric and volumetric energy density, cost, and other parameters and offer some perspectives in the area of Mg/S batteries.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163868/1/eom212056.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163868/2/eom212056-sup-0001-supinfo.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163868/3/eom212056_am.pd