Yuhong Li

Peanut shell, a common biowaste with a huge annual production volume, was rarely selected as raw material for hard carbon applied in sodium-ion batteries, due to its high content of amorphous lignin and hemicellulose. Here, an environment-friendly open-and-stitch strategy is proposed for the first time, using peanut shells as raw material, to prepare hard carbon material rich in closed pores, since closed pores provide low-voltage plateau capacity without decreasing the initial Coulombic efficiency (ICE). Dilute HCl solution is employed in partial hydrolysis to regulate the microstructure of peanut shells, and small amount of disodium ethylenediamine tetraacetate (Na2EDTA) is used in followed calcination to construct closed pores by stitching the open surface. The product provides 388.7 mAh∙g-1 reversible capacity with an ICE of 74.4% at 30 mA∙g-1, and retains 260.7 mAh∙g-1 at 150 mA∙g‑1 after 500 discharge-charge cycles. This study gives new insight into constructing closed pores in biowaste-derived hard carbon for high-performance anode material of sodium-ion batteries, with environmental-friendly and cost-effective method.

Two oxygen migration behaviours during the H₂¹⁷O–ZnO interactions were observed by ¹⁷O NMR spectroscopy, namely, surface dynamic exchange and subsurface diffusion.

Based on the morphology and experimental spectra of ZnO nanorods, the ¹⁷O solid-state NMR signal at −18.8 ppm is proved to arise from both (101̄0) and (0002) exposed facets.

SiC MOSFET has the small junction capacitance and low gate charge, and its witching processes are fast in both dv/dt and di/dt. Due to the presence of large stray inductors in traditional wire bonding (WB) packages, a series of drawbacks such as oscillations and electromagnetic interference will occur at higher di/dt. This paper mainly studies the device spurious parameters and thermal performance under the package of different structures by simulation based on the advantages of all-copper interconnects. By studying the stray parameters and thermal performance generated by different interconnect methods, the optimal interconnect model is selected to lay the theoretical foundation for subsequent sample production. We find that the all-copper interconnected package model with ceramic heat dissipation has the best heat dissipation effect. It also has absolute advantages in reducing parasitic inductance and parasitic resistance. This provides a good theoretical basis for subsequent actual production.

In this paper, the relevant failure analysis is carried out for the electric leakage problem of the product in the H3TRB process. It is discovered that ion migration existed in the metal layer in the chip. According to the conditions of ion migration, we have experimentally verified by changing different materials and verifying the reliability of the product, and it can be seen that the failure is strongly related to the air tightness of the material. It is found that when the material's air tightness reached a certain level, the product did not fail in H3TRB (1000H). Therefore, filling materials with better air tightness around the chip can prevent ion migration in the product in H3TRB. This is also the main solution for the DFN 0603 package to achieve high reliability and mass production.