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Poly(ethylene oxide)-coated sulfur/carbon (S/C/PEO) composite with a high sulfur loading is prepared to improve the performance of lithium-sulfur batteries. By magnetic string, 3.7 wt% PEO is coated onto the surface of ball-milling obtained S/C composite, leading to synthesis of S/C/PEO composite containing 78 wt% S. It is confirmed from a series of measurements that PEO covers the S/C composite uniformly, and PEO coating is quite effective in stabilizing the electrochemical performance. When employed as cathode for lithium-sulfur batteries, S/C/PEO delivers an initial discharge capacity of 989.6 mAh g and remains 648.3 mAh g after 110 cycles at a discharge/charge rate of 1 C (based on sulfur weight). Meanwhile, the coulomb efficiency of S/C/PEO composite reaches to ~98 % during the latter 105 cycles. The improved electrochemical performance can be attributed to the formation of PEO coating layer which can keep a tight contact between carbon and sulfur and lead to improved conductivity. Moreover, the PEO coating can act as a flexible cushion to accommodate volume changes of sulfur cathode as well as a barrier to trap soluble polysulfide intermediates during the charge-discharge processes. [ABSTRACT FROM AUTHOR]

Pouch cells are assembled to evaluate the Li 4 Ti 5 O 12 +AC/LiMn 2 O 4 +AC hybrid battery capacitor system. Different composite method is discussed and the Li 4 Ti 5 O 12 +AC/LiMn 2 O 4 +AC cell shows better electrochemical performance. In comparison with different composite proportions and C N /C P ratios, the results show that the cell with a C N /C P ratio 1.01, containing 5 wt% AC in each electrode, embraced superior electrochemical performance. Capacity loss is less than 22.5% after 2000 cycles at 5 C, achieving a large improvement of the cycle stability compared to Li 4 Ti 5 O 12 /LiMn 2 O 4 lithium-ion battery. Then large prismatic prototype is designed, the excellent cycle stability makes it a promising device for public utilization of these energy storage applications. [ABSTRACT FROM AUTHOR]

Abstract: Electrochemical method with salt as electrolyte has been studied to disintegrate the graphite matrix from the simulative high temperature gas-cooled reactor fuel elements. Ammonium nitrate was experimentally chosen as the appropriate electrolyte. The volume average diameter of disintegrated graphite fragments is about 100μm and the maximal value is less than 900μm. After disintegration, the weight of graphite is found to increase by about 20% without the release of a large amount of CO2 probably owing to the partial oxidation to graphite in electrochemical process. The present work indicates that the improved electrochemical method has the potential to reduce the secondary nuclear waste and is a promising option to disintegrate graphite matrix from high temperature gas-cooled reactor spent fuel elements in the head-end of reprocessing. [Copyright &y& Elsevier]