Reasonable design and applications of graphene-based materials are supposed to be promising ways to tackle many fundamental problems emerging in lithium batteries,including suppression of electrode/electrolyte side re...Reasonable design and applications of graphene-based materials are supposed to be promising ways to tackle many fundamental problems emerging in lithium batteries,including suppression of electrode/electrolyte side reactions,stabilization of electrode architecture,and improvement of conductive component.Therefore,extensive fundamental research on this aspect has been performed so far.However,when it comes to large-scale industrial applications,the utilization of graphene-based materials progresses at a very slow pace.Namely,there presents a severe technological decoupling between academic research and industrial application,and there is an urgent need to link them.Herein,in order to address current issues of graphene-based materials used in lithium batteries,we present their latest advancements with stateof-the-art technologies.Potential applications of graphenebased materials in practical lithium batteries are highlighted and predicted to bridge the gap between the academic progress and industrial manufacture,thereby paving the way for accelerating the development of graphenebased material as well as lithium battery industry.展开更多
Detection of cracks is a great concern in production and operation processes of graphene based devices to ensure uniform quality.Here,we show a detection method for graphene cracks by electromagnetic induction.The tim...Detection of cracks is a great concern in production and operation processes of graphene based devices to ensure uniform quality.Here,we show a detection method for graphene cracks by electromagnetic induction.The time varying magnetic field leads to induced voltage signals on graphene,and the signals are detected by a voltmeter.The measured level of induced voltage is correlated with the number of cracks in graphene positively.The correlation is attributed to the increasing inductive characteristic of defective graphene,and it is verified by electromagnetic simulation and radio frequency analysis.Furthermore,we demonstrate that the induced voltage signal is insensitive to the doping level of graphene.Our work can potentially lead to the development of a high-throughput and reliable crack inspection technique for mass production of graphene applications.展开更多
Sodium-ion batteries hold great promise as next-generation energy storage systems.However,the high instability of the electrode/electrolyte interphase during cycling has seriously hindered the development of SIBs.In p...Sodium-ion batteries hold great promise as next-generation energy storage systems.However,the high instability of the electrode/electrolyte interphase during cycling has seriously hindered the development of SIBs.In particular,an unstable cathode–electrolyte interphase(CEI)leads to successive electrolyte side reactions,transition metal leaching and rapid capacity decay,which tends to be exacerbated under high-voltage conditions.Therefore,constructing dense and stable CEIs are crucial for high-performance SIBs.This work reports localized high-concentration electrolyte by incorporating a highly oxidation-resistant sulfolane solvent with non-solvent diluent 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether,which exhibited excellent oxidative stability and was able to form thin,dense and homogeneous CEI.The excellent CEI enabled the O3-type layered oxide cathode NaNi_(1/3)Mn_(1/3)Fe_(1/3)O_(2)(NaNMF)to achieve stable cycling,with a capacity retention of 79.48%after 300 cycles at 1 C and 81.15%after 400 cycles at 2 C with a high charging voltage of 4.2 V.In addition,its nonflammable nature enhances the safety of SIBs.This work provides a viable pathway for the application of sulfolane-based electrolytes on SIBs and the design of next-generation high-voltage electrolytes.展开更多
Two-dimensional(2D)transition metal borides(MBenes)have emerged as a rising star and hold great potential promise for catalysis and metal ion batteries owing to a well-defined layered structure and ex-cellent electric...Two-dimensional(2D)transition metal borides(MBenes)have emerged as a rising star and hold great potential promise for catalysis and metal ion batteries owing to a well-defined layered structure and ex-cellent electrical conductivity.Unlike well-studied graphene,perovskite and MXene materials in various fields,the research about MBene is still in its infancy.The inadequate exploration of efficient etching methods impedes their further study.Herein,we put forward an efficient microwave-assisted hydrother-mal alkaline solution etching strategy for exfoliating MoAlB MAB phase into 2D MoB MBenes with a well accordion-like structure,which displays a remarkable electrochemical performance in sodium ion batter-ies(SIBs)with a reversible specific capacity of 196.5 mAh g^(-1)at the current density of 50 mA g^(-1),and 138.6 mAh g^(-1)after 500 cycles at the current density of 0.5 A g^(-1).The underlying mechanism toward excellent electrochemical performance are revealed by comprehensive theoretical simulations.This work proves that MBene is a competitive candidate as the next generation anode of sodium ion batteries.展开更多
The transition to renewable energy sources has elevated the importance of SIBs(SIBs)as cost-effective alternatives to lithium-ion batteries(LIBs)for large-scale energy storage.This review examines the mechanisms of ga...The transition to renewable energy sources has elevated the importance of SIBs(SIBs)as cost-effective alternatives to lithium-ion batteries(LIBs)for large-scale energy storage.This review examines the mechanisms of gas generation in SIBs,identifying sources from cathode materials,anode materials,and electrolytes,which pose safety risks like swelling,leakage,and explosions.Gases such as CO_(2),H_(2),and O_(2) primarily arise from the instability of cathode materials,side reactions between electrode and electrolyte,and electrolyte decomposition under high temperatures or voltages.Enhanced mitigation strategies,encompassing electrolyte design,buffer layer construction,and electrode material optimization,are deliberated upon.Accordingly,subsequent research endeavors should prioritize long-term high-precision gas detection to bolster the safety and performance of SIBs,thereby fortifying their commercial viability and furnishing dependable solutions for large-scale energy storage and electric vehicles.展开更多
The exfoliation of bulk graphitic carbon nitride(g-C_(3)N_(4))into monolayer has been intensively studied to induce maximum sur-face area for fundamental studies,but ended in failure to realize chemi-cally and physica...The exfoliation of bulk graphitic carbon nitride(g-C_(3)N_(4))into monolayer has been intensively studied to induce maximum sur-face area for fundamental studies,but ended in failure to realize chemi-cally and physically well-defined monolayer of g-C_(3)N_(4)mostly due to the difficulty in reducing the layer thickness down to an atomic level.It has,therefore,remained as a challenging issue in two-dimensional(2D)chemistry and physics communities.In this study,an“atomic monolayer of g-C_(3)N_(4)with perfect two-dimensional limit”was successfully prepared by the chemically well-defined two-step routes.The atomically resolved monolayer of g-C_(3)N_(4)was also confirmed by spectroscopic and micro-scopic analyses.In addition,the experimental Cs-HRTEM image was collected,for the first time,which was in excellent agreement with the theoretically simulated;the evidence of monolayer of g-C_(3)N_(4)in the perfect 2D limit becomes now clear from the HRTEM image of orderly hexagonal symmetry with a cavity formed by encirclement of three adjacent heptazine units.Compared to bulk g-C_(3)N_(4),the present g-C_(3)N_(4)monolayer showed significantly higher photocatalytic gen-eration of H2O2 and H2,and electrocatalytic oxygen reduction reaction.In addition,its photocatalytic efficiency for H2O2 production was found to be the best for any known g-C_(3)N_(4)nanomaterials,underscoring the remarkable advantage of monolayer formation in optimizing the catalyst performance of g-C_(3)N_(4).展开更多
The isolated inorganic particles within composite polymer electrolytes(CPEs) are not correlated to the Li^(+)transfer network,resulting in the polymer dominating the low ionic conductivity of CPEs.Therefore,we develop...The isolated inorganic particles within composite polymer electrolytes(CPEs) are not correlated to the Li^(+)transfer network,resulting in the polymer dominating the low ionic conductivity of CPEs.Therefore,we developed novel quasi-solid-state CPEs of a Ce-doped Na super ion conductors(NASICON)Na_(1.3+x)Al_(0.3)Ce_(x)Ti_(1.7-x)(PO_(4))_(3)(NCATP) chemically coupled poly(vinylidene fluoride-hexafluoropropylene)(PVDF-HFP)/Li-bis(trifluoromethanes-ulfonyl)imide(LiTFSI) matrix.A strong interaction between Ce^(3+)from NCATP and TFSI-anion from the polymer matrix contributes to the fast Li+transportation at the interface.The PVDF-HFP/NCATP CPEs exhibit an ionic conductivity of 2.16 × 0^(-3) S cm^(-1) and a Li^(+) transference number of 0.88.A symmetric Li/Li cell with NCATP-integrated CPEs at 0.1 mA cm^(-2) presents outstanding cycling stability over 2000 h at 25℃.The quasi-solid-state Li metal batteries of Li/CPEs/LiFePO_(4) at 2 C after 400 cycles and Li/CPEs/LiCoO_(2) at 0.2 C after 120 cycles deliver capacities of 100 and 152 mAh g^(-1) at 25℃,respectively.展开更多
Sodium-ion batteries (NIBs) have become an ideal alternative to lithium-ion batteries in the field of electrochemical energy storage due to their abundant raw materials and cost-effectiveness. With the progress of hum...Sodium-ion batteries (NIBs) have become an ideal alternative to lithium-ion batteries in the field of electrochemical energy storage due to their abundant raw materials and cost-effectiveness. With the progress of human society, the requirements for energy storage systems in extreme environments, such as deep-sea exploration, aerospace missions, and tunnel operations, have become more stringent. The comprehensive performance of NIBs at low temperatures (LTs) has also become an important consideration. Under LT conditions, challenges such as increased viscosity of electrolyte, abnormal growth of solid electrolyte interface, and poor contact between collector and electrode materials emerge. The aforementioned issues hinder the diffusion kinetics of sodium ions (Na^(+)) at the electrode/electrolyte interface and cause rapid degradation of battery performance. Consequently, the optimization of electrolyte composition and cathode/anode materials becomes an effective approach to improve LT performance. This review discusses the conduction behavior and limiting factors of Na^(+) in both solid electrodes and liquid electrolytes at LT. Furthermore, it systematically reviews the recent research progress of LT NIBs from three aspects: cathode materials, anode materials, and electrolyte components. This review aims to provide a valuable reference for developing high-performance LT NIBs.展开更多
This work demonstrates a novel polymerization-derived polymer electrolyte consisting of methyl methacrylate,lithium bis(trifluoromethanesulfonyl)imide and fluoroethylene carbonate.The polymerization of MMA was initiat...This work demonstrates a novel polymerization-derived polymer electrolyte consisting of methyl methacrylate,lithium bis(trifluoromethanesulfonyl)imide and fluoroethylene carbonate.The polymerization of MMA was initiated by the amino compounds following an anionic catalytic mechanism.LiTFSI plays both roles including the initiator and Li ion source in the polymer electrolyte.Normally,lithium bis(trifluoromethanesulfonyl)imide has difficulty in initiating the polymerization reaction of methyl methacrylate monomer,a very high concentration of lithium bis(trifluoromethanesulfonyl)imide is needed for initiating the polymerization.However,the fluoroethylene carbonate additive can work as a supporter to facilitate the degree of dissociation of lithium bis(trifluoromethanesulfonyl)imide and increase its initiator capacity due to the high dielectric constant.The as-prepared poly-methyl methacrylate-based polymer electrolyte has a high ionic conductivity(1.19×10^(−3)S cm^(−1)),a wide electrochemical stability window(5 V vs Li^(+)/Li),and a high Li ion transference number(t_(Li^(+)))of 0.74 at room temperature(RT).Moreover,this polymerization-derived polymer electrolyte can effectively work as an artificial protective layer on Li metal anode,which enabled the Li symmetric cell to achieve a long-term cycling performance at 0.2 mAh cm^(−2)for 2800 h.The LiFePO_(4)battery with polymerization-derived polymer electrolyte-modified Li metal anode shows a capacity retention of 91.17%after 800 cycles at 0.5 C.This work provides a facile and accessible approach to manufacturing poly-methyl methacrylate-based polymerization-derived polymer electrolyte and shows great potential as an interphase in Li metal batteries.展开更多
Graphite tailings produced by natural graphite is usually regarded as garbage to be buried underground,which would result in a certain waste of resources.Here,in order to explore the utilization of natural graphite ta...Graphite tailings produced by natural graphite is usually regarded as garbage to be buried underground,which would result in a certain waste of resources.Here,in order to explore the utilization of natural graphite tailings(NGT),a liquid-polyacrylonitrile(LPAN)is used to modify the NGT fragments and aggregate them together to form secondary graphite particles with low surface area and high tap density.Moreover,the modified NGT show much better electrochemical performances than those of original one.When tested in full cells coupled with NMC532 cathode,the material achieves a high rate capability and cycle stability at the cutoff voltage of 4.25 V as well as 4.45 V,which maintains 84.32%capacity retention after 500 cycles at 1 C rate(4.25 V),higher than that of the pristine one(73.65%).The enhanced performances can be attributed to the use of LPAN to create a unique carbon layer upon graphite tailings to reconstruct surface and repair defects,and also to granulate an isotropic structure of secondary graphite particles,which can help to weaken the anisotropy of Li^(+)diffusion pathway and form a uniform,complete and stable solid-electrolyte-interface(SEI)on the surface of primary NGT fragments to promote a fast Li+diffusion and suppress lithium metal dendrites upon charge and discharge.展开更多
Rechargeable lithium batteries with high-capacity cathodes/anodes promise high energy densities for nextgeneration electrochemical energy storage.However,the associated limitations at various scales greatly hinder the...Rechargeable lithium batteries with high-capacity cathodes/anodes promise high energy densities for nextgeneration electrochemical energy storage.However,the associated limitations at various scales greatly hinder their practical applications.Functional gradient material(FGM)design endows the electrode materials with property gradient,thus providing great opportunities to address the kinetics and stability obstacles.To date,still no review or perspective has covered recent advancements in gradient design at multiple scales for boosting lithium battery performances.To fill this void,this work provides a timely and comprehensive overview of this exciting and sustainable research field.We begin by overviewing the fundamental features of FGM and the rationales of gradient design for improved electrochemical performance.Then,we comprehensively review FGM design for rechargeable lithium batteries at various scales,including natural or artificial solid electrolyte interphase(SEI)at the nanoscale,micrometer-scale electrode particles,and macroscale electrode films.The link between gradient structure design and improved electrochemical performance is particularly highlighted.The most recent research into constructing novel functional gradients,such as valence and temperature gradients,has also been explored.Finally,we discussed the current constraints and future scope of FGM in rechargeable lithium batteries,aiming to inspire the development of novel FGM for next-generation high-performance lithium batteries.展开更多
In this study,the morphological distribution of Ru on nitrogen-doped graphene(NG)could be rationally regulated via modulating the combination mode between Ru precursor and the zeolite imidazolate framework-8(ZIF-8).Th...In this study,the morphological distribution of Ru on nitrogen-doped graphene(NG)could be rationally regulated via modulating the combination mode between Ru precursor and the zeolite imidazolate framework-8(ZIF-8).The cation exchange and host-vip strategies respectively resulted in two different combination modes between Ru precursor and ZIF-8 anchored on graphene.Following pyrolysis of the above precursors,Ru single-atom sites(SASs)with and without Ru nanoparticles(NPs)were formed selectively on NG(denoted as Ru SASs+NPs/NG and Ru SASs/NG,respectively).Ru SASs+NPs/NG exhibited excellent hydrogen evolution reaction(HER)performance in alkaline solutions(η_(10)=12 mV,12.57 A mg^(-1)_(Ru) at 100 mV),which is much better than Ru SASs/NG.The experimental and theoretical study revealed that Ru SASs could adsorb hydrogen with optimal adsorption strength,while Ru NPs could lower the barrier of water molecule dissociation,and thus Ru SASs and Ru NPs could synergistically promote the catalytic performance of HER in alkaline solutions.展开更多
In this work, we report the electrical field tuning of magneto-phonon resonance in monolayer graphene under magnetic fields up to 9 T. It is found that the carrier concentration can drastically affect the G （E2g） ph...In this work, we report the electrical field tuning of magneto-phonon resonance in monolayer graphene under magnetic fields up to 9 T. It is found that the carrier concentration can drastically affect the G （E2g） phonon response to a varying magnetic field through a pronounced magneto-phonon resonance （MPR）. In charge neutral or slightly doped monolayer graphene, both the energy and the line width of the E2g phonon show clear variation with magnetic fields. This is attributed to magneto-phonon resonance between magnetoexcitations and the E2g phonons. In contrast, when the Fermi level of the monolayer graphene is far away from the Dirac point, the G band shows weak magnetic dependence and exhibits a symmetric line-shape. This suggests that the magneto-phonon coupling around 4 T has been switched off due to the Pauli blocking of the inter-Landau level excitations. Moreover, the G band asymmetry caused by Fano resonance between excitonic many-body states and the E2g phonons is observed. This work offers a way to study the magnetoexcitation phonon interaction of materials through magneto-Raman spectroscopy with an external electrical field.展开更多
We report the thermal conductivities of monolayer （1L） and bilayer （2L） WS2 grown by chemical vapor deposition （CVD）, which are determined by use of temperature and excitation dependences of E2g^1 and A1g Raman ...We report the thermal conductivities of monolayer （1L） and bilayer （2L） WS2 grown by chemical vapor deposition （CVD）, which are determined by use of temperature and excitation dependences of E2g^1 and A1g Raman modes. The first-order temperature coefficients of E2g^1 and Alg modes in both supported and suspended WS2 layers were extracted. The frequency shift of the A3g mode with temperature is larger than that of the E1 mode for 1L-WS2, which is 2g attributed to stronger electron-phonon coupling for the A1g mode than that for the E12g mode. Moreover, by use of the shift of the phonon mode induced by laser heating, the thermal conductivities at room temperature were estimated to be 32 and 53 W/（m.K） for 1L- and 2L-WS2, respectively. Our results provide fundamental information about the thermal properties of WS2 layers, which is crucial for developing applications of atomically-thin WS2 devices.展开更多
In the recent years, transition-metal dichalcogenides such as MoS2 have attracted considerable attention owing to their unique structure and electronic properties. Chemical vapor deposition （CVD） is a popular method...In the recent years, transition-metal dichalcogenides such as MoS2 have attracted considerable attention owing to their unique structure and electronic properties. Chemical vapor deposition （CVD） is a popular method for producing MoS2 flakes with different shapes. Here, we report an effective method for achieving a broad range of shape evolution in CVD-grown monolayer MoS2 flakes. By controlling the S and MoO3 temperatures, the shape of the monolayer MoS2 flakes was varied from hexagonal to triangular via intermediate shapes such as truncated and multi-apex triangles. The shape evolution of the MoS2 flakes can be explained by introducing the term “nominal Mo：S ratio”, which refers to the amount of loaded MoO3 and evaporated S powders. By using the nominal Mo：S ratio, we predicted the potential reaction atmosphere and effectively controlled the actual proportion of MoO3-x with respect to S in the growth region, along with the growth temperature. From the systematic investigation of the behavior of the shape evolution, we developed a shape-evolution diagram, which can be used as a practical guide for producing CVD-grown MoS2 flakes with desired shapes展开更多
In this study,dual-metal atomic pairs of manganese(Mn)-iron(Fe)binuclear sites(BNSs)with two conjoint MnN4 and FeN4 moieties(MnFeN8)anchored onto a graphite-like structure(GLS)(Mn-Fe BNSs/GLS)were constructed.The binu...In this study,dual-metal atomic pairs of manganese(Mn)-iron(Fe)binuclear sites(BNSs)with two conjoint MnN4 and FeN4 moieties(MnFeN8)anchored onto a graphite-like structure(GLS)(Mn-Fe BNSs/GLS)were constructed.The binuclear MnFeN8 structure was verified experimentally and theoretically.Magnetic measurements and Gaussian calculations reveal that this unique Mn-Fe BNSs exhibit strong short-range electronic interaction between Mn and Fe sites,which decouples two paired d electrons in Fe sites,thereby transforming Fe sites from an intermediate to a high spin state.The optimal electronic configuration of Fe sites and their binuclear structure facilitate an oxygen reduction reaction(ORR)thermodynamically and dynamically,respectively,endowing Mn-Fe BNSs with improved ORR performance.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2020YFC1909604)the Natural Science Foundation of China(Nos.52202269 and 52002248)+1 种基金Shenzhen Science and Technology program(No.20220810155330003)Shenzhen Basic Research Program(No.JCYJ20190808163005631)。
文摘Reasonable design and applications of graphene-based materials are supposed to be promising ways to tackle many fundamental problems emerging in lithium batteries,including suppression of electrode/electrolyte side reactions,stabilization of electrode architecture,and improvement of conductive component.Therefore,extensive fundamental research on this aspect has been performed so far.However,when it comes to large-scale industrial applications,the utilization of graphene-based materials progresses at a very slow pace.Namely,there presents a severe technological decoupling between academic research and industrial application,and there is an urgent need to link them.Herein,in order to address current issues of graphene-based materials used in lithium batteries,we present their latest advancements with stateof-the-art technologies.Potential applications of graphenebased materials in practical lithium batteries are highlighted and predicted to bridge the gap between the academic progress and industrial manufacture,thereby paving the way for accelerating the development of graphenebased material as well as lithium battery industry.
文摘Detection of cracks is a great concern in production and operation processes of graphene based devices to ensure uniform quality.Here,we show a detection method for graphene cracks by electromagnetic induction.The time varying magnetic field leads to induced voltage signals on graphene,and the signals are detected by a voltmeter.The measured level of induced voltage is correlated with the number of cracks in graphene positively.The correlation is attributed to the increasing inductive characteristic of defective graphene,and it is verified by electromagnetic simulation and radio frequency analysis.Furthermore,we demonstrate that the induced voltage signal is insensitive to the doping level of graphene.Our work can potentially lead to the development of a high-throughput and reliable crack inspection technique for mass production of graphene applications.
基金financial support by National Natural Science Foundation(NNSF)of China(Nos.52202269,52002248,U23B2069,22309162)Shenzhen Science and Technology program(No.20220810155330003)+1 种基金Shenzhen Basic Research Project(No.JCYJ20190808163005631)Xiangjiang Lab(22XJ01007).
文摘Sodium-ion batteries hold great promise as next-generation energy storage systems.However,the high instability of the electrode/electrolyte interphase during cycling has seriously hindered the development of SIBs.In particular,an unstable cathode–electrolyte interphase(CEI)leads to successive electrolyte side reactions,transition metal leaching and rapid capacity decay,which tends to be exacerbated under high-voltage conditions.Therefore,constructing dense and stable CEIs are crucial for high-performance SIBs.This work reports localized high-concentration electrolyte by incorporating a highly oxidation-resistant sulfolane solvent with non-solvent diluent 1H,1H,5H-octafluoropentyl-1,1,2,2-tetrafluoroethyl ether,which exhibited excellent oxidative stability and was able to form thin,dense and homogeneous CEI.The excellent CEI enabled the O3-type layered oxide cathode NaNi_(1/3)Mn_(1/3)Fe_(1/3)O_(2)(NaNMF)to achieve stable cycling,with a capacity retention of 79.48%after 300 cycles at 1 C and 81.15%after 400 cycles at 2 C with a high charging voltage of 4.2 V.In addition,its nonflammable nature enhances the safety of SIBs.This work provides a viable pathway for the application of sulfolane-based electrolytes on SIBs and the design of next-generation high-voltage electrolytes.
基金supported by the National Key Re-search and Development Program of China(No.2020YFC1909604)SZIIT Startup Fund(No.SZIIT2022KJ072)+1 种基金Shenzhen Peacock Project Startup Fund(No.RC2023-002)Shenzhen Steady General Projects(No.KJ2024C010).
文摘Two-dimensional(2D)transition metal borides(MBenes)have emerged as a rising star and hold great potential promise for catalysis and metal ion batteries owing to a well-defined layered structure and ex-cellent electrical conductivity.Unlike well-studied graphene,perovskite and MXene materials in various fields,the research about MBene is still in its infancy.The inadequate exploration of efficient etching methods impedes their further study.Herein,we put forward an efficient microwave-assisted hydrother-mal alkaline solution etching strategy for exfoliating MoAlB MAB phase into 2D MoB MBenes with a well accordion-like structure,which displays a remarkable electrochemical performance in sodium ion batter-ies(SIBs)with a reversible specific capacity of 196.5 mAh g^(-1)at the current density of 50 mA g^(-1),and 138.6 mAh g^(-1)after 500 cycles at the current density of 0.5 A g^(-1).The underlying mechanism toward excellent electrochemical performance are revealed by comprehensive theoretical simulations.This work proves that MBene is a competitive candidate as the next generation anode of sodium ion batteries.
基金financial support of Shenzhen Science and Technology Program(No.KJZD20230923115005009)Xiangjiang Lab(22XJ01007)+3 种基金National Natural Science Foundation(NNSF)of China(No.52202269)Shenzhen Science and Technology program(No.20220810155330003)Shenzhen Science and Technology Program(NO.KJZD20230923115005009)Project of Department of Education of Guangdong Province(No.2022ZDZX3018).
文摘The transition to renewable energy sources has elevated the importance of SIBs(SIBs)as cost-effective alternatives to lithium-ion batteries(LIBs)for large-scale energy storage.This review examines the mechanisms of gas generation in SIBs,identifying sources from cathode materials,anode materials,and electrolytes,which pose safety risks like swelling,leakage,and explosions.Gases such as CO_(2),H_(2),and O_(2) primarily arise from the instability of cathode materials,side reactions between electrode and electrolyte,and electrolyte decomposition under high temperatures or voltages.Enhanced mitigation strategies,encompassing electrolyte design,buffer layer construction,and electrode material optimization,are deliberated upon.Accordingly,subsequent research endeavors should prioritize long-term high-precision gas detection to bolster the safety and performance of SIBs,thereby fortifying their commercial viability and furnishing dependable solutions for large-scale energy storage and electric vehicles.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2020R1I1A1A01072161)and under the framework of the International Cooperation Program managed by NRF(No.2017K2A9A2A10013104)supported by the NRF grant funded by the Korea government(MSIP)(No.NRF-2020R1A2C3008671).
文摘The exfoliation of bulk graphitic carbon nitride(g-C_(3)N_(4))into monolayer has been intensively studied to induce maximum sur-face area for fundamental studies,but ended in failure to realize chemi-cally and physically well-defined monolayer of g-C_(3)N_(4)mostly due to the difficulty in reducing the layer thickness down to an atomic level.It has,therefore,remained as a challenging issue in two-dimensional(2D)chemistry and physics communities.In this study,an“atomic monolayer of g-C_(3)N_(4)with perfect two-dimensional limit”was successfully prepared by the chemically well-defined two-step routes.The atomically resolved monolayer of g-C_(3)N_(4)was also confirmed by spectroscopic and micro-scopic analyses.In addition,the experimental Cs-HRTEM image was collected,for the first time,which was in excellent agreement with the theoretically simulated;the evidence of monolayer of g-C_(3)N_(4)in the perfect 2D limit becomes now clear from the HRTEM image of orderly hexagonal symmetry with a cavity formed by encirclement of three adjacent heptazine units.Compared to bulk g-C_(3)N_(4),the present g-C_(3)N_(4)monolayer showed significantly higher photocatalytic gen-eration of H2O2 and H2,and electrocatalytic oxygen reduction reaction.In addition,its photocatalytic efficiency for H2O2 production was found to be the best for any known g-C_(3)N_(4)nanomaterials,underscoring the remarkable advantage of monolayer formation in optimizing the catalyst performance of g-C_(3)N_(4).
基金the National Key Research and Development Program of China (No. 2020YFC1909604)the Shenzhen Key Projects of Technological Research (JSGG2020092514 5800001)。
文摘The isolated inorganic particles within composite polymer electrolytes(CPEs) are not correlated to the Li^(+)transfer network,resulting in the polymer dominating the low ionic conductivity of CPEs.Therefore,we developed novel quasi-solid-state CPEs of a Ce-doped Na super ion conductors(NASICON)Na_(1.3+x)Al_(0.3)Ce_(x)Ti_(1.7-x)(PO_(4))_(3)(NCATP) chemically coupled poly(vinylidene fluoride-hexafluoropropylene)(PVDF-HFP)/Li-bis(trifluoromethanes-ulfonyl)imide(LiTFSI) matrix.A strong interaction between Ce^(3+)from NCATP and TFSI-anion from the polymer matrix contributes to the fast Li+transportation at the interface.The PVDF-HFP/NCATP CPEs exhibit an ionic conductivity of 2.16 × 0^(-3) S cm^(-1) and a Li^(+) transference number of 0.88.A symmetric Li/Li cell with NCATP-integrated CPEs at 0.1 mA cm^(-2) presents outstanding cycling stability over 2000 h at 25℃.The quasi-solid-state Li metal batteries of Li/CPEs/LiFePO_(4) at 2 C after 400 cycles and Li/CPEs/LiCoO_(2) at 0.2 C after 120 cycles deliver capacities of 100 and 152 mAh g^(-1) at 25℃,respectively.
基金Guangdong High-level Innovation Institute Project,Grant/Award Number:2021 B0909050001National Natural Science Foundation(NNSF)of China,Grant/Award Number:22309162GRINM Young Scholar Funding Project,National Natural Science Foundation of China,Grant/Award Number:12104024。
文摘Sodium-ion batteries (NIBs) have become an ideal alternative to lithium-ion batteries in the field of electrochemical energy storage due to their abundant raw materials and cost-effectiveness. With the progress of human society, the requirements for energy storage systems in extreme environments, such as deep-sea exploration, aerospace missions, and tunnel operations, have become more stringent. The comprehensive performance of NIBs at low temperatures (LTs) has also become an important consideration. Under LT conditions, challenges such as increased viscosity of electrolyte, abnormal growth of solid electrolyte interface, and poor contact between collector and electrode materials emerge. The aforementioned issues hinder the diffusion kinetics of sodium ions (Na^(+)) at the electrode/electrolyte interface and cause rapid degradation of battery performance. Consequently, the optimization of electrolyte composition and cathode/anode materials becomes an effective approach to improve LT performance. This review discusses the conduction behavior and limiting factors of Na^(+) in both solid electrodes and liquid electrolytes at LT. Furthermore, it systematically reviews the recent research progress of LT NIBs from three aspects: cathode materials, anode materials, and electrolyte components. This review aims to provide a valuable reference for developing high-performance LT NIBs.
基金funded by the National Key Research and Development Program of China(no.2020YFC1909604)Shenzhen Key Projects of Technological Research(JSGG20200925145800001)Shenzhen Basic Research Project(no.JCYJ20190808145203535).
文摘This work demonstrates a novel polymerization-derived polymer electrolyte consisting of methyl methacrylate,lithium bis(trifluoromethanesulfonyl)imide and fluoroethylene carbonate.The polymerization of MMA was initiated by the amino compounds following an anionic catalytic mechanism.LiTFSI plays both roles including the initiator and Li ion source in the polymer electrolyte.Normally,lithium bis(trifluoromethanesulfonyl)imide has difficulty in initiating the polymerization reaction of methyl methacrylate monomer,a very high concentration of lithium bis(trifluoromethanesulfonyl)imide is needed for initiating the polymerization.However,the fluoroethylene carbonate additive can work as a supporter to facilitate the degree of dissociation of lithium bis(trifluoromethanesulfonyl)imide and increase its initiator capacity due to the high dielectric constant.The as-prepared poly-methyl methacrylate-based polymer electrolyte has a high ionic conductivity(1.19×10^(−3)S cm^(−1)),a wide electrochemical stability window(5 V vs Li^(+)/Li),and a high Li ion transference number(t_(Li^(+)))of 0.74 at room temperature(RT).Moreover,this polymerization-derived polymer electrolyte can effectively work as an artificial protective layer on Li metal anode,which enabled the Li symmetric cell to achieve a long-term cycling performance at 0.2 mAh cm^(−2)for 2800 h.The LiFePO_(4)battery with polymerization-derived polymer electrolyte-modified Li metal anode shows a capacity retention of 91.17%after 800 cycles at 0.5 C.This work provides a facile and accessible approach to manufacturing poly-methyl methacrylate-based polymerization-derived polymer electrolyte and shows great potential as an interphase in Li metal batteries.
基金the financial support of National Key Research and Development Program of China(No.2020YFC1909604)National Natural Science Foundation(NNSF)of China(Nos.52202269,52002248)+1 种基金Shenzhen Key Projects of Technological Research(No.JSGG20200925145800001)and Shenzhen Basic Research Project(Nos.JCYJ20190808145203535,JCYJ20190808163005631)for providing financial support for this work.We are also grateful to the Instrumental Analysis Center of Shenzhen University(Xili Campus)for providing the facilities for our material analyzes。
文摘Graphite tailings produced by natural graphite is usually regarded as garbage to be buried underground,which would result in a certain waste of resources.Here,in order to explore the utilization of natural graphite tailings(NGT),a liquid-polyacrylonitrile(LPAN)is used to modify the NGT fragments and aggregate them together to form secondary graphite particles with low surface area and high tap density.Moreover,the modified NGT show much better electrochemical performances than those of original one.When tested in full cells coupled with NMC532 cathode,the material achieves a high rate capability and cycle stability at the cutoff voltage of 4.25 V as well as 4.45 V,which maintains 84.32%capacity retention after 500 cycles at 1 C rate(4.25 V),higher than that of the pristine one(73.65%).The enhanced performances can be attributed to the use of LPAN to create a unique carbon layer upon graphite tailings to reconstruct surface and repair defects,and also to granulate an isotropic structure of secondary graphite particles,which can help to weaken the anisotropy of Li^(+)diffusion pathway and form a uniform,complete and stable solid-electrolyte-interface(SEI)on the surface of primary NGT fragments to promote a fast Li+diffusion and suppress lithium metal dendrites upon charge and discharge.
基金financial support from the National Natural Science Foundation of China(Nos.52261160384 and 52072208)the Project of Department of Education of Guangdong Province(No.2022ZDZX3018)+2 种基金the Natural Science Foundation of Guangdong(No.2023A1515010020)the Innovation and Technology Fund(No.ITS-325-22FP)the Shenzhen Science and Technology Program(No.KJZD20230923114107014)。
文摘Rechargeable lithium batteries with high-capacity cathodes/anodes promise high energy densities for nextgeneration electrochemical energy storage.However,the associated limitations at various scales greatly hinder their practical applications.Functional gradient material(FGM)design endows the electrode materials with property gradient,thus providing great opportunities to address the kinetics and stability obstacles.To date,still no review or perspective has covered recent advancements in gradient design at multiple scales for boosting lithium battery performances.To fill this void,this work provides a timely and comprehensive overview of this exciting and sustainable research field.We begin by overviewing the fundamental features of FGM and the rationales of gradient design for improved electrochemical performance.Then,we comprehensively review FGM design for rechargeable lithium batteries at various scales,including natural or artificial solid electrolyte interphase(SEI)at the nanoscale,micrometer-scale electrode particles,and macroscale electrode films.The link between gradient structure design and improved electrochemical performance is particularly highlighted.The most recent research into constructing novel functional gradients,such as valence and temperature gradients,has also been explored.Finally,we discussed the current constraints and future scope of FGM in rechargeable lithium batteries,aiming to inspire the development of novel FGM for next-generation high-performance lithium batteries.
基金supported by the National Key Research and Development Program of China(2020YFC1909604)Shenzhen Key Projects of Technological Research(JSGG20200925145800001)+1 种基金Shenzhen Basic Research Project(JCYJ20190808145203535,JCYJ20190808144413257)the Project of Natural Science Foundation of Guangdong Province(2020A1515010379)。
文摘In this study,the morphological distribution of Ru on nitrogen-doped graphene(NG)could be rationally regulated via modulating the combination mode between Ru precursor and the zeolite imidazolate framework-8(ZIF-8).The cation exchange and host-vip strategies respectively resulted in two different combination modes between Ru precursor and ZIF-8 anchored on graphene.Following pyrolysis of the above precursors,Ru single-atom sites(SASs)with and without Ru nanoparticles(NPs)were formed selectively on NG(denoted as Ru SASs+NPs/NG and Ru SASs/NG,respectively).Ru SASs+NPs/NG exhibited excellent hydrogen evolution reaction(HER)performance in alkaline solutions(η_(10)=12 mV,12.57 A mg^(-1)_(Ru) at 100 mV),which is much better than Ru SASs/NG.The experimental and theoretical study revealed that Ru SASs could adsorb hydrogen with optimal adsorption strength,while Ru NPs could lower the barrier of water molecule dissociation,and thus Ru SASs and Ru NPs could synergistically promote the catalytic performance of HER in alkaline solutions.
文摘In this work, we report the electrical field tuning of magneto-phonon resonance in monolayer graphene under magnetic fields up to 9 T. It is found that the carrier concentration can drastically affect the G （E2g） phonon response to a varying magnetic field through a pronounced magneto-phonon resonance （MPR）. In charge neutral or slightly doped monolayer graphene, both the energy and the line width of the E2g phonon show clear variation with magnetic fields. This is attributed to magneto-phonon resonance between magnetoexcitations and the E2g phonons. In contrast, when the Fermi level of the monolayer graphene is far away from the Dirac point, the G band shows weak magnetic dependence and exhibits a symmetric line-shape. This suggests that the magneto-phonon coupling around 4 T has been switched off due to the Pauli blocking of the inter-Landau level excitations. Moreover, the G band asymmetry caused by Fano resonance between excitonic many-body states and the E2g phonons is observed. This work offers a way to study the magnetoexcitation phonon interaction of materials through magneto-Raman spectroscopy with an external electrical field.
文摘We report the thermal conductivities of monolayer （1L） and bilayer （2L） WS2 grown by chemical vapor deposition （CVD）, which are determined by use of temperature and excitation dependences of E2g^1 and A1g Raman modes. The first-order temperature coefficients of E2g^1 and Alg modes in both supported and suspended WS2 layers were extracted. The frequency shift of the A3g mode with temperature is larger than that of the E1 mode for 1L-WS2, which is 2g attributed to stronger electron-phonon coupling for the A1g mode than that for the E12g mode. Moreover, by use of the shift of the phonon mode induced by laser heating, the thermal conductivities at room temperature were estimated to be 32 and 53 W/（m.K） for 1L- and 2L-WS2, respectively. Our results provide fundamental information about the thermal properties of WS2 layers, which is crucial for developing applications of atomically-thin WS2 devices.
文摘In the recent years, transition-metal dichalcogenides such as MoS2 have attracted considerable attention owing to their unique structure and electronic properties. Chemical vapor deposition （CVD） is a popular method for producing MoS2 flakes with different shapes. Here, we report an effective method for achieving a broad range of shape evolution in CVD-grown monolayer MoS2 flakes. By controlling the S and MoO3 temperatures, the shape of the monolayer MoS2 flakes was varied from hexagonal to triangular via intermediate shapes such as truncated and multi-apex triangles. The shape evolution of the MoS2 flakes can be explained by introducing the term “nominal Mo：S ratio”, which refers to the amount of loaded MoO3 and evaporated S powders. By using the nominal Mo：S ratio, we predicted the potential reaction atmosphere and effectively controlled the actual proportion of MoO3-x with respect to S in the growth region, along with the growth temperature. From the systematic investigation of the behavior of the shape evolution, we developed a shape-evolution diagram, which can be used as a practical guide for producing CVD-grown MoS2 flakes with desired shapes
基金supported by the National Key Research and Development Program of China (2020YFC1909604)Shenzhen Key Projects of Technological Research (JSGG20200925145800001)Shenzhen Science and Technology Program (CJGJZD20210408092801005)。
基金financially supported by the National Natural Science Foundation of China(11921006)the National Key Research and Development Program of China(2020YFC1909604)+1 种基金Shenzhen Key Projects of Technological Research(JSGG20200925145800001)Shenzhen Science and Technology Program(CJGJZD20210408092801005)。
基金MOE2016-T2-1-131(Tier 2)Singapore was acknow-ledged.the National Natural Science Foundation of China (Nos.11274380,91433103, 11622437,and 61674171)the Fundamental Research Funds for the Central Universities,China and the Research Funds of Renmin University of China (No.16XNLQ01)Calculations were performed at the pkysics lab of high-performance computing of Renmin University of China.
基金support of Shenzhen Basic Research Project(Nos.JCYJ20170818092720054,JCYJ20190808145203535,and JCYJ20190808144413257)National Natural Science Foundation of China(No.21671136)+3 种基金Postdoctoral Science Foundation of China(No.2019M663085)Major Programs for Science and Technology Development of Shenzhen(Nos.JSGG20160328151657828 and XCL201110060)Major Industrial Projects of Shenzhen(No.s2017001850011)the Project of Natural Science Foundation of Guangdong Province(Nos.2020A1515010380 and 2014A030311028).
文摘In this study,dual-metal atomic pairs of manganese(Mn)-iron(Fe)binuclear sites(BNSs)with two conjoint MnN4 and FeN4 moieties(MnFeN8)anchored onto a graphite-like structure(GLS)(Mn-Fe BNSs/GLS)were constructed.The binuclear MnFeN8 structure was verified experimentally and theoretically.Magnetic measurements and Gaussian calculations reveal that this unique Mn-Fe BNSs exhibit strong short-range electronic interaction between Mn and Fe sites,which decouples two paired d electrons in Fe sites,thereby transforming Fe sites from an intermediate to a high spin state.The optimal electronic configuration of Fe sites and their binuclear structure facilitate an oxygen reduction reaction(ORR)thermodynamically and dynamically,respectively,endowing Mn-Fe BNSs with improved ORR performance.
