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One-step hydrothermal synthesis of Fe<sub>2</sub>O<sub>3</sub>@TiO<sub>2</sub> microspheres with high lithium storage performance
摘要： The precursor of Fe(OH)3, C and TiO2 was synthesized by a simple one-step hydrothermal method. Then, the of C in the composite was eliminated by calcination at 500 ℃ for 5h in an air atmosphere. Thereby, a Fe2O3@TiO2 microspheres composite material is synthesized. The incorporation of Fe2O3 helps provide high specific capacity, high speed cycling and stable life performance. The first discharge capacity is 688mAh/g, with higher discharge capacity of Fe2O3@TiO2 microspheres (372mAh/g), and with the insertion/extraction of Li+ during charge and discharge, a dense SEI (Solid Electrolyte Interface) film is formed on the surface of the material to cause actual discharge of the graphite carbon material. The capacity is relatively low since the graphite carbon material has a lower theoretical specific capacity. The 2nd to 50th charge and discharge of Fe2O3@TiO2 microspheres, the capacitance retention rate exceeds 90%. The outstanding stable cycling and well rate performance suggest that Fe2O3@TiO2 microspheres have great potential to be applied as anode material for lithium ion batteries.
关键词： Anode,Carbon,Titanium dioxide,Ferric oxide,Lithium ion battery
更新于2025-09-10 09:29:36
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Big Potential From Silicon-Based Porous Nanomaterials: In Field of Energy Storage and Sensors
摘要： Silicon nanoparticles (SiNPs) are the promising materials in the various applications due to their unique properties like large surface area, biocompatibility, stability, excellent optical and electrical properties. Surface, optical and electrical properties are highly dependent on particle size, doping of different materials and so on. Porous structures in silicon nanomaterials not only improve the specific surface area, adsorption, and photoluminescence efficiency but also provide numbers of voids as well as the high surface to volume ratio and enhance the adsorption ability. In this review, we focus on the significance of porous silicon/mesoporous silicon nanoparticles (pSiNPs/mSiNPs) in the applications of energy storage, sensors and bioscience. Silicon as anode material in the lithium-ion batteries (LIBs) faces a huge change in volume during charging/discharging which leads to cracking, electrical contact loss and unstable solid electrolyte interphase. To overcome challenges of Si anode in the LIBs, mSiNPs are the promising candidates with different structures and coating of different materials to enhance electrochemical properties. On the basis of optical properties with tunable wavelength, pSiNPs are catching good results in biosensors and gas sensors. The mSiNPs with different structures and modified surfaces are playing an important role in the detection of biomarkers, drug delivery and diagnosis of cancer and tumors.
关键词： lithium ion battery,silicon nanomaterials,bioapplication,porous structures,core shell
更新于2025-09-09 09:28:46
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[IEEE 2018 International Power Electronics Conference (IPEC-Niigata 2018 –ECCE Asia) - Niigata, Japan (2018.5.20-2018.5.24)] 2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia) - DC powered data center with 200 kW PV panels
摘要： Power consumption of ICT facilities and data centers has grown, and this has led to a need to improve energy efficiency of these facilities. DC power distribution systems employing 380VDC as the supply voltage is one promising approach to address this problem for countries around the world developing and deploying commercial services. The international team by the university of Texas, Austin, USA and NTT FACILITIEIS, Japan demonstrated a 380VDC power distribution system interconnected with a solar power generation system in Texas, USA. The purpose of this demonstration was to show that a 380VDC power supply system saves more energy than an AC power supply system, and to show how much carbon dioxide emissions can be reduced by integrating a solar power generation system. This demonstration resulted in an approximate 17% energy reduction compared with an AC power supply system having the same level of reliability. Also, an evaluation using Data center Performance Per Energy (DPPE) as a performance index of the efficiency of data centers was carried out. The results showed that Power Usage Effectiveness (PUE), one of the sub-metrics of DPPE, improved with the 380VDC power supply system compared with the AC power supply system.
关键词： 380 VDC,Lithium Ion Battery,PV panel,Data center
更新于2025-09-09 09:28:46
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Effect of Defects on Diffusion Behaviors of Lithium-ion Battery Electrodes: In Situ Optical Observation and Simulation
摘要： Lithium-ion batteries (LIBs) with high energy efficiency are urgeniltly needed in various fields. For the LIBs electrodes, defects would be generated during manufacture processes and mechanical degradation, and the defects significantly impact the stability and performance of LIBs. However, the effects of electrode defects on the electrochemical processes are still not clear. Herein, an in situ optical observation system is developed for monitoring the Li diffusion around the pre-introduced defects in the commercial graphite electrodes. The experiments show the gas-filled defects vertical to the direction of the Li diffusion would obviously decelerate Li diffusion, while the electrolyte-filled defects parallel to the direction of the Li diffusion would accelerate Li diffusion. In addition, finite element analysis (FEA) suggests consistent with the experiments, showing nonuniform distribution of local Li concentration around the defect. The equivalent diffusivity obtained by FEA is also dependent on the configuration of the defects. The diffusivities of electrolyte-filled parallel defect and gas-filled vertical defect are 12.6 % and 11.0 %, respectively. For the gas-filled defects, the size-effect calculation manifests that equivalent diffusivity would decrease with the enlarged defect size, and the shape of the defects would substantially impact the decrease rate. The results directly reveal the mechanisms of defect induced diffusion behavior change in the electrodes by the new equivalent 2D experiments, and the equivalent diffusivity would be useful for optimizing electrode designs in LIBs.
关键词： colorimetric method,defect,graphite anode,lithium-ion battery,diffusion
更新于2025-09-09 09:28:46
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Estimation of state of charge of lithium-ion battery based on photovoltaic generation energy storage system
摘要： The fast and accurate estimation of state of charge (SOC) of lithium-ion battery is one of the key technologies of battery management system. In view of this nonlinear dynamic system of lithium battery, through the test and analysis of lithium-ion battery hysteresis characteristics, the second-order RC hysteresis model is established, and the cubature Kalman filter algorithm is used to estimate the battery state of charge in this report. The experiment results show that the battery model can essentially predict the dynamic hysteresis voltage behavior of the lithium-ion battery and cubature Kalman Filtering algorithm can maintain high accuracy in the estimation process.
关键词： cubature Kalman filter,Lithium-ion battery,state of charge,hysteresis model
更新于2025-09-09 09:28:46
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The Impact of Initial SEI Formation Conditions on Strain‐Induced Capacity Losses in Silicon Electrodes
摘要： The solid electrolyte interphase (SEI) that passivates silicon surfaces in Li ion batteries is subjected to extremely large mechanical strains during electrochemical cycling. The resulting degradation of these SEI films is a critical problem that limits the cycle life of silicon-based electrodes. With the complex multiphase microstructure in conventional porous electrodes, it is not possible to directly measure the impact of these strains on SEI formation and capacity loss. To overcome this limitation a new in situ method is presented for applying controlled mechanical strains to SEI during electrochemical cycling. This approach uses patterned silicon films with different sized islands that act as model electrode particles. During lithiation/delithiation, the lateral expansion/contraction of the island edges applies in plane strains to the SEI. Detailed analysis of the island size effect then provides quantitative measurements of the impact of strain on the excess capacity losses that occur in different potential ranges. One key finding is that the applied strains lead to large capacity losses during lithiation only (during all cycles). Also, employing fast and slow SEI formation (first cycle) leads to large differences in the strain-induced losses that occur during subsequent cycling.
关键词： shear lag zone,lithium-ion battery,capacity loss,SEI formation
更新于2025-09-04 15:30:14