2D polyaniline with exchangeable interlayer fluid for fast and stable volumetric dual ion storage

Two-dimensional(2D) layered materials are widely applied in energy devices including lithium-ion battery and supercapacitor due to their unique properties,such as tunable interlayer structure,numerous active sites,large aspect ratio versatile interlayer chemistry.In this work,2D layered tungstate acidlinked polyaniline(TALP) presented a fluid-in-solid structure,which allowed facile exchange of the interlayer fluid from moisture to conventional Li^(+) containing electrolyte.With fast and stable dual ion storage(Li^(+) and PF_(6)^(-)),TALP demonstrates high-rate volumetric capacity(39 mAh cm_(-3) at 2000 mA g^(-1)) and good stability(2000 cycles at 200 mA g^(-1)) within the working potential window of 1.5-4.5 V versus Li^(+)/Li.

Charging-rate-based Battery Energy Storage System in Wind Farm and Battery Storage Cooperation Bidding Problem

Wind power has been proven to have the ability to participate in the frequency modulation(FM)market.Using batteries to improve wind power stability can better aid wind farms participating in the FM market.Battery energy storage system(BESS)has a promising future in applying regulation and load management in the power grid.For regulation services,normally,the regulation power prediction is estimated based on the required maximum regulation capacity;the power needed for the specific regulation service is unknown to the BESS owner.However,this information is needed in the regulation model when formulating the linearised BESS model with a constraint on the state of charge(SoC).This compromises the accuracy of the model greatly when it is applied for regulation service.Moreover,different control strategies can be employed by BESS.However,the current depth of discharge(DoD)based models have difficulties in being used in a linearization problem.Due to the consideration of the control strategy,the model becomes highly nonlinear and cannot be solved.In this paper,a charging rate(C-rate)based model is introduced,which can consider different control strategies of a BESS for cooperation with wind farms to participate in wind farm estimation error compensation,load management,energy bid,and regulation bid.First,the limitation of conventional BESS models are listed,and a new C-rate-based model is introduced.Then the C-rate-based BESS model is adopted in a wind farm and BESS cooperation scheme.Finally,experimental studies are carried out,and the DoD model and C-rate model optimization results are compared to prove the rationality of the C-rate model.

Demystifying the catalysis in lithium–sulfur batteries:Characterizationmethods and techniques

Lithium–sulfur(Li-S)batteries are promising next-generation energy storage systems with ultrahigh energy density.However,the intrinsic sluggish“solid–liquid–solid”reaction between S8 and Li2S causes unavoidable shuttling of polysulfides,severely limiting the practical energy density and cycling performance.Recently,the catalysis process has been introduced for the sulfur redox reaction to accelerate the conversion of polysulfides,providing a positive remedy for the polysulfides shuttling.Nevertheless,in-depth understanding of the catalyst evaluation criteria and catalytic mechanism still lies in the“black box”,and precise characterization technique is the key to unlock this puzzle.In this review,we provide a comprehensive overview of characterization techniques on the catalyst in Li-S batteries from two aspects of catalytic performance and catalytic mechanism,highlighting their significance and calling for more efforts to develop precise and fast techniques for Li-S catalysis.Moreover,we envision the future development of characterization for better understanding the catalysis toward practical Li-S battery.

Optimal operation of integrated energy system including power thermal and gas subsystems

As a form of hybrid multi-energy systems,the integrated energy system contains different forms of energy such as power,thermal,and gas which meet the load of various energy forms.Focusing mainly on model building and optimal operation of the integrated energy system,in this paper,the dist-flow method is applied to quickly calculate the power flow and the gas system model is built by the analogy of the power system model.In addition,the piecewise linearization method is applied to solve the quadratic Weymouth gas flow equation,and the alternating direction method of multipliers(ADMM)method is applied to narrow the optimal results of each subsystem at the coupling point.The entire system reaches its optimal operation through multiple iterations.The power-thermal-gas integrated energy system used in the case study includes an IEEE-33 bus power system,a Belgian 20 node natural gas system,and a six node thermal system.Simulation-based calculations and comparison of the results under different scenarios prove that the power-thermal-gas integrated energy system enhances the flexibility and stability of the system as well as reducing system operating costs to some extent.