Analysis of the Comprehensive Physical Field for a New Flywheel Energy Storage Motor/Generator on Ships

A novel flywheel energy storage （FES） motor/generator （M/G） was proposed for marine systems. The purpose was to improve the power quality of a marine power system （MPS） and strengthen the energy recycle. Two structures including the magnetic or non-magnetic inner-rotor were contrasted in the magnetostatic field by using finite element analysis （FEA）. By optimally designing the size parameters, the average speed of FEA results of was 17 200 r/m, and the current was controlled between 62 and 68 A in the transient field. The electrical machine electromagnetism design was further optimized by the FEA in the temperature field, to find the local overheating point under the normal operation condition and provide guidance for the cooling system. Finally, it can be concluded from the comprehensive physical field analysis that the novel redundant structure M/G can improve the efficiency of the M/G and maintain the stability of the MPS.

Catholyte engineering to release the capacity of iodide for high-energy-density iodine-based redox flow batteries

Due to the high solubility,high reversibility,and low cost of iodide,iodine-based redox flow batteries(RFBs)are considered to have great potential for upscaling energy storage.However,their further development has been limited by the low capacity of I−as one-third of the I−is used to form I3−(I2I−)during the charging process.Herein,we have demonstrated that the pseudohalide ion,thiocyanate(SCN−),is a promising complexing agent for catholyte of iodinebased RFBs to free up the I−by forming iodine-thiocyanate ions([I2SCN]−)instead of I3−,unlocking the capacity of iodide.Applying this strategy,we have demonstrated iodine-based RFBs with full utilization of iodide to achieve high capacity and high energy density.Both the zinc/iodine RFB and polysulfide/iodine RFB with SCN−complex agent achieve their theoretical capacity of around 160 A h Lposolyte^(−1)(6.0MI−in catholyte).Therefore,the zinc/iodine RFB delivers a high energy density of 221.34Wh Lposolyte^(−1),and the polysulfide/iodine RFB achieves a highenergy density of 165.62Wh Lposolyte^(−1).It is believed that this effective catholyte engineering can be further generalized to other iodine-based RFBs,offering new opportunities to unlock the capacity of iodide and achieve high energy density for energy storage.

Recent advances in flexible batteries:From materials to applications

Along with the rapid development of flexible and wearable electronic devices,there have been a strong demand for flexible power sources,which has in turn triggered considerable efforts on the research and development of flexible batteries.An ideal flexible battery would have not only just high electrochemical performance but also excellent mechanical deformabilities.Therefore,battery constituent components,chemistry systems,device configurations,and practical applications are all pivotal aspects that should be thoroughly considered.Herein,we systematically and comprehensively review the fundamentals and recent progresses of flexible batteries in terms of these important aspects.Specifically,we first discuss the requirements for constituent components,including the current collector,electrolyte,and separator,in flexible batteries.We then elucidate battery chemistry systems that have been studied for various flexible batteries,including lithium-ion batteries,non-lithium-ion batteries,and high-energy metal batteries.This is followed by discussions on the device configurations for flexible batteries,including onedimensional fiber-shaped,two-dimensional film-shaped,and three-dimensional structural batteries.Finally,we summarize recent efforts in exploring practical applications for flexible batteries.Current challenges and future opportunities for the research and development of flexible batteries are also discussed.