Understanding the mechanism of capacity increase during early cycling of commercial NMC/graphite lithium-ion batteries

A capacity increase is often observed in the early stage of Li-ion battery cycling.This study explores the phenomena involved in the capacity increase from the full cell,electrodes,and materials perspective through a combination of non-destructive diagnostic methods in a full cell and post-mortem analysis in a coin cell.The results show an increase of 1%initial capacity for the battery aged at 100%depth of discharge(DOD)and 45℃.Furthermore,large DODs or high temperatures accelerate the capacity increase.From the incremental capacity and differential voltage(IC-DV)analysis,we concluded that the increased capacity in a full cell originates from the graphite anode.Furthermore,graphite/Li coin cells show an increased capacity for larger DODs and a decreased capacity for lower DODs,thus in agreement with the full cell results.Post-mortem analysis results show that a larger DOD enlarges the graphite dspace and separates the graphite layer structure,facilitating the Li+diffusion,hence increasing the battery capacity.

Understanding the phenomenon of capacity increasing along cycles: In the case of an ultralong-life and high-rate SnSe-Mo-C anode for lithium storage

A good cycling stability is a prerequisite for the application of metal-based materials in lithium-ion batteries(LIBs). However, an abnormal increase in capacity is often observed, which has rarely been focused on in many studies. In our SnSe-Mo-C composite anode, a high reversible capacity of 737.4 mAh g^(-1)remained after 5000 cycles at 5 A g^(-1)between 0.01 and 3.0 V versus Li/Li+. However, a continuous capacity increase occurred in the initial cycles, with 1086.9 mAh g^(-1)after 1000 cycles and 1216.9 mAh g^(-1)after 1500 cycles, respectively. Further studies revealed that the electrolyte decomposed at high potentials(2.5–3.0 V) and provided additional capacities. The cut-off voltage and electrolyte filling were controlled, which eliminated the impact of electrolyte decomposition, prevented rapid capacity decay, and provided a stable cycling performance for SnSe-Mo-C anodes in LIBs. This work shows that the composite anode is promising for lithium storage and the findings provide new insights into understanding and controlling the phenomenon of capacity increase with cycling in metal-based anode materials.

Slope stability of increasing height and expanding capacity of south dumping site of Hesgoula coal mine:a case study

This paper is devoted to improve the containment capacity of the Hesgoula south dumping site.The general geology of the dumping site was obtained through geological surveys.Physico-mechanical properties of silty clay and bedrock layers that have a large impact on the stability of the dump were measured by direct shear tests and triaxial tests in laboratory.Then ultimate bearing capacity of the substrate were analyzed and calculated.This paper proposed three capacity expansion and increase plans and used GeoStudio software for comparison.Through computation of the stability of the dump site slope after capacity expansion and increase for each plan,the capacity expansion plan was determined.The capacity expansion and increase plan will solve the problem of the current insufficient containment capacity of the Hesgoula south dumping site,which is of great significance for saving mine transportation costs,improving work efficiency,and reducing grassland occupation.

China will Strictly Control Increase of Aluminum Capacity

'In 2017,the nonferrous metals industry performed well in growth rate,structure and benefits.'Chen Quanxun,President of the China Nonferrous Metals Industry Association(CNMIA),said at the recently-held eighth meeting of the third Council of the CNMIA,

Effect of fagade systems on the performance of cooling ceilinss： In situ measurements

This article presents an innovative facade system designed to increase the thermal comfort inside an office room and to enhance the cooling capacity of the suspended cooling ceiling. A series of measurements is conducted in an existing office building with different facade systems （i.e., a combination of grazing and shading）. An innovative facade system is devetoped based on this intensive set of measurements. The new system enhances the thermal comfort and cooling capacity of the suspended cooling ceiling. The main usage of the new system is the refurbishment and improvement of existing facade systems.