Effect of Co Ion Implantation on GMR of [NiFeCo(10 nm)/Ag(10 nm)]×20 Multilayer Film

The composition, phase structure and microstructure of the discontinuous multilayer film[NiFeCo（10 nm）/Ag（10 nm）]×20 were investigated after Co ion implantation and annealing at 280, 320,360 and 400℃, respectively.GMR （giant magnetoresistance） ratio of the film with/without Co ion implantation was measured. The results showed that Co ion implantation decreased the granule size of the annealed multilayer film, and increased Hc value and GMR ratio of the multilayer film. After annealing at 360℃, the multilayer film [NiFeCo（10 nm）/Ag（10 nm）]×20 with/without Co ion implantation both exhibited the highest GMR ratio of 12.4%/11% under 79.6 kA/m of applied saturation magnetic field.

Facile hydrothermal and sol-gel synthesis of novel Sn-Co/C composite as superior anodes for Li-ion batteries

As an anode material in lithium ion battery,the Sn-Co/C composite electrode materials have been successfully synthesized by hydrothermal and sol-gel methods,respectively.The resultant composites were mainly composed of Sn-based oxides,nanometer Sn-Co alloy and carbon.Carbon and Co,acting as buffer materials,can accommodate to the large volume change of active Sn during the discharge-charge process,thus improving the cycling stability.Although charge/discharge curves revealed the excellent cycle performance for samples synthesized by both methods,composites obtained by the sol-gel showed a better dispersion effect of nanoparticles on the carbon matrix and possessed much more improved stable capacity with*624.9 mAh g-1over 100 cycles and that by hydrothermal method only exhibited*299.3 mAh g-1.Therefore,the Sn-Co/C composites obtained by sol-gel synthesis method could be a perfect candidate for anode material of Li-ion storage battery.

Influence of structure and atom sites on Sn-based anode materials for lithium ion batteries: a first-principle study

To understand the influence of structure and atom sites on the electrochemical properties of Sn-based anode materials,the lithium intercalation–deintercalation mechanisms into SnNi2Cu and SnNiCu2phases were studied using the first-principle plane wave pseudo-potential method.Calculation results showed that both SnNi2Cu and SnNiCu2were unsuitable anode materials for lithium ion batteries.The Sn-based anode structure related to the number of interstitial sites,theoretical specific capacity,and volume expansion ratio.Different atom sites led to different forces at interstitial sites,resulting in variations in formation energy,density of states,and hybrid orbital types.In order to validate the calculated model,the SnNi2Cu alloy anode material was synthesized through a chemical reduction-codeposition approach.Experimental results proved that the theoretical design was reasonable.Consequently,when selecting Snbased alloy anodes,attention should be paid to maximizing the number of interstitial sites and distributing atoms reasonably to minimize forces at these sites and facilitate the intercalation and deintercalation of lithium ion.

Hierarchically 3D structured milled lamellar MoS2/nano-silicon@carbon hybrid with medium capacity and long cycling sustainability as anodes for lithium-ion batteries

A hierarchically 3D structured milled lamellar MoS2/nano-siIicon@carbon hybrid with medium capacity and long-term lifespan is designed by a green and scalable approach using ball milling process and spraydrying/ pyrolysis routes. The microspheres consist of low-content nano-silicon (20 wt%), milled lamellar M0S2 sheets and porous carbon skeletons. A mixture of silicon nanoparticles and M0S2 flakes serves as an inner core, while porous carbon pyrolyzed from petroleum pitch acts as a protective shell. The particular architecture affords robust mechanical support, abundant buffering space and enhanced electrical conductivity, thus effectively accommodating drastic volume variation during repetitive Li+ intercalation/ extraction. The Si/MoS2@C hybrid delivers a high initial discharge specific capacity of 1257.8 mA hg^-1 and exhibits a reversible capacity of 767.52 m A hg^-1 at a current density 100 mA g'1 after 250 cycles. Most impressively, the electrode depicts a superior long-cycling durability with a discharge capacity of 537.6 mA hg^-1 even after 1200 cycles at a current density of 500 m A g^-1. Meanwhile, the hybrid also shows excellent rate performance such as 388.1 mA h g^-1 even at a large current density of 3000 mA g^-1.