A comparative study of data-driven battery capacity estimation based on partial charging curves

With its generality and practicality, the combination of partial charging curves and machine learning(ML) for battery capacity estimation has attracted widespread attention. However, a clear classification,fair comparison, and performance rationalization of these methods are lacking, due to the scattered existing studies. To address these issues, we develop 20 capacity estimation methods from three perspectives:charging sequence construction, input forms, and ML models. 22,582 charging curves are generated from 44 cells with different battery chemistry and operating conditions to validate the performance. Through comprehensive and unbiased comparison, the long short-term memory(LSTM) based neural network exhibits the best accuracy and robustness. Across all 6503 tested samples, the mean absolute percentage error(MAPE) for capacity estimation using LSTM is 0.61%, with a maximum error of only 3.94%. Even with the addition of 3 m V voltage noise or the extension of sampling intervals to 60 s, the average MAPE remains below 2%. Furthermore, the charging sequences are provided with physical explanations related to battery degradation to enhance confidence in their application. Recommendations for using other competitive methods are also presented. This work provides valuable insights and guidance for estimating battery capacity based on partial charging curves.

Flexible bidirectional pulse charging regulation achieving long-life lithium-ion batteries

Typical application scenarios,such as vehicle to grid(V2G)and frequency regulation,have imposed significant long-life demands on lithium-ion batteries.Herein,we propose an advanced battery life-extension method employing bidirectional pulse charging(BPC)strategy.Unlike traditional constant current charging methods,BPC strategy not only achieves comparable charging speeds but also facilitates V2G frequency regulation simultaneously.It significantly enhances battery cycle ampere-hour throughput and demonstrates remarkable life extension capabilities.For this interesting conclusion,adopting model identification and postmortem characterization to reveal the life regulation mechanism of BPC:it mitigates battery capacity loss attributed to loss of lithium-ion inventory(LLI)in graphite anodes by intermittently regulating the overall battery voltage and anode potential using a negative charging current.Then,from the perspective of internal side reaction,the life extension mechanism is further revealed as inhibition of solid electrolyte interphase(SEI)and lithium dendrite growth by regulating voltage with a bidirectional pulse current,and a semi-empirical life degradation model combining SEI and lithium dendrite growth is developed for BPC scenarios health management,the model parameters are identified by genetic algorithm with the life simulation exhibiting an accuracy exceeding 99%.This finding indicates that under typical rate conditions,adaptable BPC strategies can extend the service life of LFP battery by approximately 123%.Consequently,the developed advanced BPC strategy offers innovative perspectives and insights for the development of long-life battery applications in the future.

ZnO Additive Boosts Charging Speed and Cycling Stability of Electrolytic Zn–Mn Batteries

Electrolytic aqueous zinc-manganese(Zn–Mn) batteries have the advantage of high discharge voltage and high capacity due to two-electron reactions. However, the pitfall of electrolytic Zn–Mn batteries is the sluggish deposition reaction kinetics of manganese oxide during the charge process and short cycle life. We show that, incorporating ZnO electrolyte additive can form a neutral and highly viscous gel-like electrolyte and render a new form of electrolytic Zn–Mn batteries with significantly improved charging capabilities. Specifically, the ZnO gel-like electrolyte activates the zinc sulfate hydroxide hydrate assisted Mn^(2+) deposition reaction and induces phase and structure change of the deposited manganese oxide(Zn_(2)Mn_(3)O_8·H_(2)O nanorods array), resulting in a significant enhancement of the charge capability and discharge efficiency. The charge capacity increases to 2.5 mAh cm^(-2) after 1 h constant-voltage charging at 2.0 V vs. Zn/Zn^(2+), and the capacity can retain for up to 2000 cycles with negligible attenuation. This research lays the foundation for the advancement of electrolytic Zn–Mn batteries with enhanced charging capability.

The principle and amelioration of lithium plating in fast-charging lithium-ion batteries

Fast charging is restricted primarily by the risk of lithium(Li)plating,a side reaction that can lead to the rapid capacity decay and dendrite-induced thermal runaway of lithium-ion batteries(LIBs).Investigation on the intrinsic mechanism and the position of Li plating is crucial to improving the fast rechargeability and safety of LIBs.Herein,we investigate the Li plating behavior in porous electrodes under the restricted transport of Li^(+).Based on the theoretical model,it can be concluded that the Li plating on the anodeseparator interface(ASI)is thermodynamically feasible and kinetically advantageous.Meanwhile,the prior deposition of metal Li on the ASI rather than the anode-current collector interface(ACI)is verified experimentally.In order to facilitate the transfer of Li^(+)among the electrode and improve the utilization of active materials without Li plating,a bilayer asymmetric anode composed of graphite and hard carbon(GH)is proposed.Experimental and simulation results suggest that the GH hybrid electrode homogenizes the lithiated-rate throughout the electrode and outperforms the pure graphite electrode in terms of the rate performance and inhibition of Li plating.This work provides new insights into the behavior of Li plating and the rational design of electrode structure.

Electrothermal Model Based Remaining Charging Time Prediction of Lithium-Ion Batteries against Wide Temperature Range

Battery remaining charging time(RCT)prediction can facilitate charging management and alleviate mileage anxiety for electric vehicles(EVs).Also,it is of great significance to improve EV users’experience.However,the RCT for a lithiumion battery pack in EVs changes with temperature and other battery parameters.This study proposes an electrothermal model-based method to accurately predict battery RCT.Firstly,a characteristic battery cell is adopted to represent the battery pack,thus an equivalent circuit model(ECM)of the characteristic battery cell is established to describe the electrical behaviors of a battery pack.Secondly,an equivalent thermal model(ETM)of the battery pack is developed by considering the influence of ambient temperature,thermal management,and battery connectors in the battery pack to calculate the temperature which is then fed back to the ECM to realize electrothermal coupling.Finally,the RCT prediction method is proposed based on the electrothermal model and validated in the wide temperature range from-20℃to 45℃.The experimental results show that the prediction error of the RCT in the whole temperature range is less than 1.5%.

Multilevel carbon architecture of subnanoscopic silicon for fast‐charging high‐energy‐density lithium‐ion batteries

Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal reserves.However,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial applications.Here,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode stability.The VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge transport.The carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction density.Consequently,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode conditions.In particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C.

Optimizing Average Electric Power During the Charging of Lithium-Ion Batteries Through the Taguchi Method

In recent times, lithium-ion batteries have been widely used owing to their high energy density, extended cycle lifespan, and minimal self-discharge rate. The design of high-speed rechargeable lithium-ion batteries faces a significant challenge owing to the need to increase average electric power during charging. This challenge results from the direct influence of the power level on the rate of chemical reactions occurring in the battery electrodes. In this study, the Taguchi optimization method was used to enhance the average electric power during the charging process of lithium-ion batteries. The Taguchi technique is a statistical strategy that facilitates the systematic and efficient evaluation of numerous experimental variables. The proposed method involved varying seven input factors, including positive electrode thickness, positive electrode material, positive electrode active material volume fraction, negative electrode active material volume fraction, separator thickness, positive current collector thickness, and negative current collector thickness. Three levels were assigned to each control factor to identify the optimal conditions and maximize the average electric power during charging. Moreover, a variance assessment analysis was conducted to validate the results obtained from the Taguchi analysis. The results revealed that the Taguchi method was an eff ective approach for optimizing the average electric power during the charging of lithium-ion batteries. This indicates that the positive electrode material, followed by the separator thickness and the negative electrode active material volume fraction, was key factors significantly infl uencing the average electric power during the charging of lithium-ion batteries response. The identification of optimal conditions resulted in the improved performance of lithium-ion batteries, extending their potential in various applications. Particularly, lithium-ion batteries with average electric power of 16 W and 17 W during charging were designed and simulated in the range of 0-12000 s using COMSOL Multiphysics software. This study efficiently employs the Taguchi optimization technique to develop lithium-ion batteries capable of storing a predetermined average electric power during the charging phase. Therefore, this method enables the battery to achieve complete charging within a specific timeframe tailored to a specificapplication. The implementation of this method can save costs, time, and materials compared with other alternative methods, such as the trial-and-error approach.

Thermal safety boundary of lithium-ion battery at different state of charge

Thermal runaway(TR)is a critical issue hindering the large-scale application of lithium-ion batteries(LIBs).Understanding the thermal safety behavior of LIBs at the cell and module level under different state of charges(SOCs)has significant implications for reinforcing the thermal safety design of the lithium-ion battery module.This study first investigates the thermal safety boundary(TSB)correspondence at the cells and modules level under the guidance of a newly proposed concept,safe electric quantity boundary(SEQB).A reasonable thermal runaway propagation(TRP)judgment indicator,peak heat transfer power(PHTP),is proposed to predict whether TRP occurs.Moreover,a validated 3D model is used to quantitatively clarify the TSB at different SOCs from the perspective of PHTP,TR trigger temperature,SOC,and the full cycle life.Besides,three different TRP transfer modes are discovered.The interconversion relationship of three different TRP modes is investigated from the perspective of PHTP.This paper explores the TSB of LIBs under different SOCs at both cell and module levels for the first time,which has great significance in guiding the thermal safety design of battery systems.

Multi-Scale X-Ray Imaging Technologies for Rechargeable Batteries

The rapid advancement in electric vehicles and electrochemical energy storage technology has raised the demands placed on rechargeable batteries.It is essential to comprehend the operational principles and degradation mechanisms of batteries across multiple scales to propel the research on rechargeable batteries for the next generation forward.Microstructure,phase information,and lattice of energy materials in both two dimensions and three dimensions can be intuitively obtained through the utilization of x-ray imaging techniques.Additionally,x-ray imaging technology is increasingly gaining attention due to its non-destructive nature and high penetrative capability,enabling in situ experiments and multi-scale spatial resolution.In this review,we initially overview the basic principles and characteristics of several key x-ray imaging technologies.Each x-ray imaging technology is tailored to specific application scenarios.Furthermore,examples of multi-scale implementations of x-ray imaging technologies in the field of rechargeable batteries are discussed.This review is anticipated to augment the comprehension of readers for x-ray imaging techniques as well as to stimulate the development of novel concepts and approaches in rechargeable battery research.

Re-delocalization of localized d-electrons in VO_(2)(R)-VS_(4)hetero-structure enables high performance of rechargeable Mg-ion batteries

Rechargeable Mg-ion batteries(MIBs)have attracted much more attentions by virtue of the high capacity from the two electrons chemistry.However,the reversible Mg^(2+)diffusion in cathode materials is restricted by the strong interactions between the high-polarized bivalent Mg^(2+)ions and anionic lattice.Herein,we design and propose a hetero-structural VO_(2)(R)-VS_(4)cathode,in which the re-delocalized d-electrons can effectively shield the polarity of Mg^(2+)ions.Theoretically,the electrons should spontaneously transfer from VS_(4)to VO_(2)(R)through the interfaces of hetero-structure due to the lower work function value of VS_(4).Furthermore,the internal electrons transfer lead to the electronic injection into VO_(2)(R)from VS_(4)and the partially broken V-V dimers,indicating the presence of lone pair electrons and charge re-delocalization.Benefiting from the shield effect of re-delocalized electrons,and the weakened attraction between cations and O/S anions enables more S^(2-)-S_(2)^(2-)redox groups to participate the electrochemical reactions and compensate the double charge of Mg^(2+)ions.Accordingly,VO_(2)(R)-VS_(4)hetero-structure exhibits a high specific capacity of 554 mA h g^(-1)at 50 mA g^(-1).It is believed that the charge re-delocalization of cathode extremely boost the Mg^(2+)ions migration for the high-capacity of MIBs.

Selection of Negative Charged Acidic Polar Additives to Regulate Electric Double Layer for Stable Zinc Ion Battery

Zinc-ion batteries are promising for large-scale electrochemical energy storage systems,which still suffer from interfacial issues,e.g.,hydrogen evolution side reaction(HER),self-corrosion,and uncontrollable dendritic Zn electrodeposition.Although the regulation of electric double layer(EDL)has been verified for interfacial issues,the principle to select the additive as the regulator is still misted.Here,several typical amino acids with different characteristics were examined to reveal the interfacial behaviors in regulated EDL on the Zn anode.Negative charged acidic polarity(NCAP)has been unveiled as the guideline for selecting additive to reconstruct EDL with an inner zincophilic H_(2)O-poor layer and to replace H_(2)O molecules of hydrated Zn^(2+)with NCAP glutamate.Taking the synergistic effects of EDL regulation,the uncontrollable interface is significantly stabilized from the suppressed HER and anti-self-corrosion with uniform electrodeposition.Consequently,by adding NCAP glutamate,a high average Coulombic efficiency of 99.83%of Zn metal is achieved in Zn|Cu asymmetrical cell for over 2000 cycles,and NH4V4O10|Zn full cell exhibits a high-capacity retention of 82.1%after 3000 cycles at 2 A g^(-1).Recapitulating,the NCAP principle posted here can quicken the design of trailblazing electrolyte additives for aqueous Zn-based electrochemical energy storage systems.

Overview of multi-stage charging strategies for Li-ion batteries

To reduce the carbon footprint in the transportation sector and improve overall vehicle efficiency,a large number of electric vehicles are being manufactured.This is due to the fact that environmental concerns and the depletion of fossil fuels have become significant global problems.Lithium-ion batteries(LIBs)have been distinguished themselves from alternative energy storage technologies for electric vehicles(EVs) due to superior qualities like high energy and power density,extended cycle life,and low maintenance cost to a competitive price.However,there are still certain challenges to be solved,like EV fast charging,longer lifetime,and reduced weight.For fast charging,the multi-stage constant current(MSCC) charging technique is an emerging solution to improve charging efficiency,reduce temperature rise during charging,increase charging/discharging capacities,shorten charging time,and extend the cycle life.However,there are large variations in the implementation of the number of stages,stage transition criterion,and C-rate selection for each stage.This paper provides a review of these problems by compiling information from the literature.An overview of the impact of different design parameters(number of stages,stage transition,and C-rate) that the MSCC charging techniques have had on the LIB performance and cycle life is described in detail and analyzed.The impact of design parameters on lifetime,charging efficiency,charging and discharging capacity,charging speed,and rising temperature during charging is presented,and this review provides guidelines for designing advanced fast charging strategies and determining future research gaps.

Enhancement of charging performance of quantum battery via quantum coherence of bath

An open quantum battery(QB)model of a single qubit system charging in a coherent auxiliary bath(CAB)consisting of a series of independent coherent ancillae is considered.According to the collision charging protocol we derive a quantum master equation and obtain the analytical solution of QB in a steady state.We find that the full charging capacity(or the maximal extractable work(MEW))of QB,in the weak QB-ancilla coupling limit,is positively correlated with the coherence magnitude of ancilla.Combining with the numerical simulations we compare with the charging properties of QB at finite coupling strength,such as the MEW,average charging power and the charging efficiency,when considering the bath to be a thermal auxiliary bath(TAB)and a CAB,respectively.We find that when the QB with CAB,in the weak coupling regime,is in fully charging,both its capacity and charging efficiency can go beyond its classical counterpart,and they increase with the increase of coherence magnitude of ancilla.In addition,the MEW of QB in the regime of relative strong coupling and strong coherent magnitude shows the oscillatory behavior with the charging time increasing,and the first peak value can even be larger than the full charging MEW of QB.This also leads to a much larger average charging power than that of QB with TAB in a short-time charging process.These features suggest that with the help of quantum coherence of CAB it becomes feasible to switch the charging schemes between the long-time slow charging protocol with large capacity and high efficiency and the short-time rapid charging protocol with highly charging power only by adjusting the coupling strength of QB-ancilla.This work clearly demonstrates that the quantum coherence of bath can not only serve as the role of“fuel”of QB to be utilized to improve the QB's charging performance but also provide an alternative way to integrate the different charging protocols into a single QB.

Electric Vehicles Lithium-Polymer Ion Battery Dynamic Behaviour Charging Identification and Modelling Scheme

Lithium-ion batteries are considered the substantial electrical storage element for electric vehicles(EVs). The battery model is the basis of battery monitoring, efficient charging, and safety management. Non-linearmodelling is the key to representing the battery and its dynamic internal parameters and performance. This paperproposes a smart scheme to model the lithium-polymer ion battery while monitoring its present charging currentand terminal voltage at various ambient conditions (temperature and relative humidity). Firstly, the suggestedframework investigated the impact of temperature and relative humidity on the charging process using the constantcurrent-constant voltage (CC-CV) charging protocol. This will be followed by monitoring the battery at thesurrounding operating temperature and relative humidity. Hence, efficient non-linear modelling of the EV batterydynamic behaviour using the Hammerstein-Wiener (H-W) model is implemented. The H-W model is considered ablack box model that can represent the battery without any mathematical equivalent circuit model which reducesthe computation complexity. Finally, the model beholds the boundaries of the charging process, not affecting onthe lifetime of the battery. Several dynamic models are applied and tested experimentally to ensure theeffectiveness of the proposed scheme under various ambient conditions where the temperature is fixed at40°C and the relative humidity (RH) at 35%, 52%, and 70%. The best fit using the H-W model reached 91.83% todescribe the dynamic behaviour of the battery with a maximum percentage of error 0.1 V which is in goodagreement with the literature survey. Besides, the model has been scaled up to represent a real EV and expressedthe significance of the proposed H-W model.

Physics-based battery SOC estimation methods:Recent advances and future perspectives

The reliable prediction of state of charge(SOC)is one of the vital functions of advanced battery management system(BMS),which has great significance towards safe operation of electric vehicles.By far,the empirical model-based and data-driven-based SOC estimation methods of lithium-ion batteries have been comprehensively discussed and reviewed in various literatures.However,few reviews involving SOC estimation focused on electrochemical mechanism,which gives physical explanations to SOC and becomes most attractive candidate for advanced BMS.For this reason,this paper comprehensively surveys on physics-based SOC algorithms applied in advanced BMS.First,the research progresses of physical SOC estimation methods for lithium-ion batteries are thoroughly discussed and corresponding evaluation criteria are carefully elaborated.Second,future perspectives of the current researches on physics-based battery SOC estimation are presented.The insights stated in this paper are expected to catalyze the development and application of the physics-based advanced BMS algorithms.

A combined computational/experimental study of anode-concerned voltage drop in aqueous primary Mg-air batteries

The voltage drop appearing at Mg anode-electrolyte interface is a critical issue for the battery power and energy density of aqueous primary Mg-air batteries.The respective voltage loss is typically assigned to the deposits layer forming on the anode surface during discharge.In this work,we experimentally and computationally investigate the critical factors affecting the voltage drop at Mg anode towards a deeper understanding of the contribution of deposit and its growth.A two-dimensional(2D)mathematical model is proposed to compute the voltage drop of Mg-0.15Ca wt.%alloy(Mg-0.15Ca)by means of a semi-empirical formulas and experiments-based modification model,considering the effect of discharge current density,the negative difference effect(NDE)and surface deposits layer itself.This model is utilized to simulate the discharge potential of the anode at predefined experimental current densities.The computed voltage drop(half-cell voltage)is in good agreement with the experimental value.The applicability of the mathematical model is successfully validated on the second material(namely high-purity Mg).

Communication-less Management Strategy for Electric Vehicle Charging in Droop-controlled Islanded Microgrids

Adopting high penetration levels of electric vehicles(EVs)necessitates the implementation of appropriate charging management systems to mitigate their negative impacts on pow-er distribution networks.Currently,most of the proposed Ev charging management techniques rely on the availability of high-bandwidth communication links.Such techniques are far from realization due to①the lack of utility-grade communica-tion systems in many cases such as secondary(low-voltage)pow-er distribution systems to which EVs are connected,rural ar-eas,remote communities,and islands,and②existing fears and concerns about the data privacy of EV users and cyber-physical security.For these cases,appropriate local control schemes are needed to ensure the adequate management of EV charging without violating the grid operation requirements.Accordingly,this paper introduces a new communication-less management strategy for EV charging in droop-controlled islanded mi-crogrids.The proposed strategy is autonomous,as it is based on the measurement of system frequency and local bus voltages.The proposed strategy implements a social charging fairness policy during periods when the microgrid distributed genera-tors(DGs)are in short supply by allocating more system capaci-ty to the EVs with less charging in the past.Furthermore,a novel communication-less EV load shedding scheme is incorpo-rated into the management strategy to provide relief to the mi-crogrid during events of severe undervoltage or underfrequency occurrences due to factors such as high loading or DG outages.Numerical simulations demonstrate the superiority of the pro-posed strategy over the state-of-the-art controllers in modulat-ing the EV charging demand to counteract microgrid instability.

Reversed charge transfer induced by nickel in Fe-Ni/Mo_(2)C@nitrogen-doped carbon nanobox for promoted reversible oxygen electrocatalysis

The interaction between metal and support is critical in oxygen catalysis as it governs the charge transfer between these two entities,influences the electronic structures of the supported metal,affects the adsorption energies of reaction intermediates,and ultimately impacts the catalytic performance.In this study,we discovered a unique charge transfer reversal phenomenon in a metal/carbon nanohybrid system.Specifically,electrons were transferred from the metal-based species to N-doped carbon,while the carbon support reciprocally donated electrons to the metal domain upon the introduction of nickel.This led to the exceptional electrocatalytic performances of the resulting Ni-Fe/Mo_(2)C@nitrogen-doped carbon catalyst,with a half-wave potential of 0.91 V towards oxygen reduction reaction(ORR)and a low overpotential of 290 m V at 10 mA cm^(-2)towards oxygen evolution reaction(OER)under alkaline conditions.Additionally,the Fe-Ni/Mo_(2)C@carbon heterojunction catalyst demonstrated high specific capacity(794 mA h g_(Zn)~(-1))and excellent cycling stability(200 h)in a Zn-air battery.Theoretical calculations revealed that Mo_(2)C effectively inhibited charge transfer from Fe to the support,while secondary doping of Ni induced a charge transfer reversal,resulting in electron accumulation in the Fe-Ni alloy region.This local electronic structure modulation significantly reduced energy barriers in the oxygen catalysis process,enhancing the catalytic efficiency of both ORR and OER.Consequently,our findings underscore the potential of manipulating charge transfer reversal between the metal and support as a promising strategy for developing highly-active and durable bi-functional oxygen electrodes.

Low-Enthalpy and High-Entropy Polymer Electrolytes for Li-Metal Battery

lonic-conductive solid-state polymer electrolytes are promising for the development of advanced lithium batteries yet a deeper understanding of their underlying ion-transfer mechanism is needed to improve performance.Here we demonstrate the low-enthalpy and high-entropy(LEHE)electrolytes can intrinsically generate remarkably free ions and high mobility,enabling them to efficiently drive lithium-ion storage.The LEHE electrolytes are constructed on the basis of introducing CsPbl_(3)perovskite quantum dots(PQDs)to strengthen PEO@LiTFSI complexes.An extremely stable cycling>1000 h at 0.3 mA cm^(-2)can be delivered by LEHE electrolytes.Also,the as-developed Li|LEHE|LiFePO_(4)cell retains 92.3%of the initial capacity(160.7 mAh g^(-1))after 200 cycles.This cycling stability is ascribed to the suppressed charge concentration gradient leading to free lithium dendrites.It is realized by a dramatic increment in lithium-ion transference number(0.57 vs 0.19)and a significant decline in ion-transfer activation energy(0.14 eV vs 0.22 eV)for LEHE electrolytes comparing with PEO@LiTFSI counterpart.The CsPbl_(3)PQDs promote highly structural disorder by inhibiting crystallization and hence endow polymer electrolytes with low melting enthalpy and high structural entropy,which in turn facilitate long-term cycling stability and excellent rate-capability of lithium-metal batteries.

Engineering hollow core-shell hetero-structure box to induce interfacial charge modulation for promoting bidirectional sulfur conversion in lithium-sulfur batteries

Severe polysulfide shuttling and sluggish sulfur redox kinetics significantly decrease sulfur utilization and cycling stability in lithium-sulfur batteries(LSBs).Herein,we develop a hollow CoO/CoP-Box core-shell heterostructure as a model and multifunctional catalyst modified on separators to induce interfacial charge modulation and expose more active sites for promoting the adsorption and catalytic conversion ability of sulfur species.Theoretical and experimental findings verify that the in-situ formed core-shell hetero-interface induces the formation of P-Co-O binding and charge redistribution to activate surface O active sites for binding lithium polysulfides(LiPSs)via strong Li-O bonding,thus strongly adsorbing with Li PSs.Meanwhile,the strong Li-O bonding weakens the competing Li-S bonding in LiPSs or Li2S adsorbed on CoO/CoP-Box surface,plus the hollow heterostructure provides abundant active sites and fast electron/Li+transfer,so reducing Li2S nucleation/dissolution activation energy.As expected,LSBs with CoO/CoP-Box modified separator and traditional sulfur/carbon black cathode display a large initial capacity of 1240 mA h g^(-1)and a long cycling stability with 300 cycles(~60.1%capacity retention)at 0.5C.Impressively,the thick sulfur cathode(sulfur loading:5.2 mg cm^(-2))displays a high initial areal capacity of 6.9 mA h cm^(-2).This work verifies a deep mechanism understanding and an effective strategy to induce interfacial charge modulation and enhance active sites for designing efficient dual-directional Li-S catalysts via engineering hollow core-shell hetero-structure.