Lightweight Reduced Graphene Oxide@MoS₂ Interlayer as Polysulfide Barrier for High-Performance Lithium–Sulfur Batteries

The further development of lithium–sulfur (Li–S) batteries is limited by the fact that the soluble polysulfide leads to the shuttle effect, thereby reducing the cycle stability and cycle life of the batteries. To address this issue, here a thin and lightweight (8 μm and 0.24 mg cm^–2) reduced graphene oxide@MoS₂ (rGO@MoS₂) interlayer between the cathode and the commercial separator is developed as a polysulfide barrier. The rGO plays the roles of both a polysulfide physical barrier and an additional current collector, while MoS₂ has a high chemical adsorption for polysulfides. The experiments demonstrate that the Li–S cell constructed with an rGO@MoS₂-coated separator shows a high reversible capacity of 1122 mAh g^–1 at 0.2 C, a low capacity fading rate of 0.116% for 500 cycles at 1 C, and an outstanding rate performance (615 mAh g^–1 at 2 C). Such an interlayer is expected to be ideal for lithium–sulfur battery applications because of its excellent electrochemical performance and simple synthesis process

Metallurgy Inspired Formation of Homogeneous Al₂O₃ Coating Layer To Improve the Electrochemical Properties of LiNi_0.8Co_0.1Mn_0.1O₂ Cathode Material

Inspired by the metallurgical process of aluminum production, a controllable and cost-effective Al₂O₃ coating strategy is introduced to improve the surface stability of LiNi_0.8Co_0.1­Mn_0.1O₂. The CO₂ is introduced to NaAlO₂ aqueous solution to generate a weak basic condition that is able to decrease the deposition rate of Al­(OH)₃ and is beneficial to the uniform coating of Al­(OH)₃ on the surface of commercial Ni_0.8Co_0.1­Mn_0.1(OH)₂ precursor. The electrochemical performance of Al₂O₃-coated LiNi_0.8Co_0.1­Mn_0.1O₂ is improved at both ordinary cutoff voltage of 4.3 V and elevated cutoff voltage of 4.5 V. With the optimized Al₂O₃ coating amount (1%), the capacity retention of the material after 60 cycles increases from 90% to 99% at 2.8–4.3 V and from 86% to 99% at 2.8–4.5 V, respectively. The Al₂O₃-coated sample also delivers a better rate capability, maintaining 117 and 131 mA h g^–1 in the voltage ranges 2.8–4.3 and 2.8 V–4.5 V at the current density of 5 C, respectively. The enhanced properties of as-prepared Al₂O₃-coated LiNi_0.8Co_0.1Mn_0.1O₂ are due to the Al₂O₃ coating layer building up a favorable interface, preventing the direct contact between the active material and electrolyte and promoting Li⁺ transmission at the interface

- Changes of CEIFI, aggregation activity, HSR, CD62P expression and PS externalization in platelets during 7-day storage at 22 ± 2°C.

<p>Data are the mean ± S.D. *<i>P</i> <0.05 as compared with platelets stored for 1 day.</p

The difference in cytosolic esterase-induced fluorescence with CMFDA between resting and activated human platelets.

<p>The activity of cytosolic esterase-induced fluorescence reaction is visualized with CMFDA. The fluorescence of resting platelets was clearly visible in laser confocal microscopy, whereas activated platelets release no or little fluorescence. A, C: Resting platelets; B, D: Activated platelets (activated by 100μM ADP); A, B: green fluorescence; C, D: bright field.</p

The change of cytosolic esterase-induced fluorescence activity in platelets during 7-day storage at 22 ± 2°C.

<p>The activity of cytosolic esterase-induced fluorescence in platelets is measured with CMFDA. *<i>P</i> <0.05 as compared with platelets stored for 1 day.</p

CD62P expression percentage on membrane of platelets during 7-day storage at 22± 2°C.

<p>A: Mouse IgG1 κ Iso control. B: platelets stored for 1 day. C: platelets stored for 3 days. D: platelets stored for 5 days. E: platelets stored for 7 days.</p

PS externalization of platelets during 7-day storage at 22 ± 2°C.

<p>A: platelets stored for 1 day. B: platelets stored for 3 days. C: platelets stored for 5 days. D: platelets stored for 7 days.</p

Correlation of platelet CEIFI with functional parameters of platelets during 7-day storage.

<p>A: Correlation to the ADP-induced aggregation activity, r = 0.9813. B: Correlation to the HSR activity, r = 0.9848. C: Correlation to the expression percentage of CD62P on platelet membrane, r = -0.9945. D: Correlation to the PS externalization percentage, r = -0.9847.</p

Aggregation curves of platelets during 7-day storage at 22 ± 2°C.

<p>A: platelets stored for 1 day. B: platelets stored for 3 days. C: platelets stored for 5 days. D: platelets stored for 7 days.</p

HSR curves of platelets during 7-day storage at 22± 2°C.

<p>A: platelets stored for 1 day. B: platelets stored for 3 days. C: platelets stored for 5 days. D: platelets stored for 7 days.</p