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Commercial graphite-based Li-ion batteries almost reached their maximum energy density limits, and the need for high-energy batteries increased tremendously. Silicon (Si) has become a viable anode; however, its enormous volume expansion limits its application. In this regard, the silicon–graphite (Si-G) composite is considered a potential anode to boost the energy density of graphite and alleviate the limitations of silicon. However, the formation of an unstable solid electrolyte interface (SEI) layer impedes its use in practical applications. Hence, constructing a stable SEI layer is crucial to attaining stable and long-term cyclability for Si-G. In this study, we investigated the influence of the Li4Ti5O12(LTO) protective coating on the Si-G composite anode toward the stable SEI layer formation. We found that the LTO coating on Si-G effectively suppresses the parasitic reaction of organic electrolytes with Si and facilitates stable SEI layer formation. In particular, the cross-sectional analysis of the LTO-Si-G electrode using transmission electron microscopy after cycling confirms the presence of stable and thin SEI. In addition, the electrode showed a higher Coulombic efficiency of 99.82%, a high specific capacity of 570.48 mAh g–1, and enhanced capacity retention of 97.7% after 75 cycles. Our findings highlight that constructing a stable SEI by encasing the Si-G surface with LTO is a promising way to enhance the cycling performance of high-energy Li-ion batteries with the Si-G composite anode.

Routing protocol for low power and lossy networks (RPL) is a popular protocol used in IPv6 based wireless Internet of Things (IoT) networks. Wireless IoT devices using RPL without centralized security management are extremely vulnerable to Sybil attacks, as a malicious node can forge multiple identities and easily conduct denial-of-service (DoS) attacks. Several countermeasures have been investigated to prevent DoS caused by Sybil attacks in RPL, but crucial limitations still remain. In this letter, a physical identification based trust path routing (PITrust) scheme that uses the received signal strength indicator (RSSI) and a centralized trust scheme to improve Sybil node detection is proposed, which is shown to improve the detection rate and packet delivery ratio when compared to other schemes.

The advancements in additive manufacturing (AM) of metals open new possibilities in the design of gas turbine parts. Especially the cooling efficiency of internal channels can be improved with more complex geometries. Naturally, AM channels have a higher surface roughness than conventionally manufactured parts, which influences the cooling air pressure loss as well as the heat transfer. Implementing novel cooling designs using AM can be possible only if the effect of increased surface roughness on the flow and on the heat transfer can be predicted with an appropriate accuracy. The objective of the current study was to measure these parameters experimentally in simple AM channels to build a database for designing complex and efficient cooling designs using the AM technique. A test rig and postprocessing method was elaborated to derive the local internal heat transfer distribution of metal-based AM channels. Six circular single channel coupons made by selective laser melting (SLM) were tested for Reynolds numbers ranging from 20,000 to 50,000. The coupon with the lowest relative roughness shows good agreement with the Dittus–Boelter correlation. All the other coupons show a consistent increase of internal heat transfer and flow friction with the increase of the internal surface roughness.