Regulation of Lithium-Ion Flux by Nanotopology Lithiophilic Boron-Oxygen Dipole in Solid Polymer Electrolytes for Lithium-Metal Batteries

Inhomogeneous lithium-ion(Li^(+))deposition is one of the most crucial problems,which severely deteriorates the performance of solid-state lithium metal batteries(LMBs).Herein,we discovered that covalent organic framework(COF-1)with periodically arranged boron-oxygen dipole lithiophilic sites could directionally guide Li^(+)even deposition in asymmetric solid polymer electrolytes.This in situ prepared 3D cross-linked network Poly(ACMO-MBA)hybrid electrolyte simultaneously delivers outstanding ionic conductivity(1.02×10^(-3)S cm^(-1)at 30°C)and excellent mechanical property(3.5 MPa).The defined nanosized channel in COF-1 selectively conducts Li^(+)increasing Li^(+)transference number to 0.67.Besides,The COF-1 layer and Poly(ACMO-MBA)also participate in forming a boron-rich and nitrogen-rich solid electrolyte interface to further improve the interfacial stability.The Li‖Li symmetric cell exhibits remarkable cyclic stability over 1000 h.The Li‖NCM523 full cell also delivers an outstanding lifespan over 400 cycles.Moreover,the Li‖LiFePO_(4)full cell stably cycles with a capacity retention of 85%after 500 cycles.the Li‖LiFePO_(4)pouch full exhibits excellent safety performance under pierced and cut conditions.This work thereby further broadens and complements the application of COF materials in polymer electrolyte for dendrite-free and high-energy-density solid-state LMBs.

Smart materials for safe lithium-ion batteries against thermal runaway

In recent years,the new energy storage system,such as lithium ion batteries(LIBs),has attracted much attention.In order to meet the demand of industrial progress for longer cycle life,higher energy density and cost efficiency,a quantity of research has been conducted on the commercial application of LIBs.However,it is difficult to achieve satisfying safety and cycling performance simultaneously.There may be thermal runaway(TR),external impact,overcharge and overdischarge in the process of battery abuse,which makes the safety problem of LIBs more prominent.In this review,we summarize recent progress in the smart safety materials design towards the goal of preventing TR of LIBs reversibly from different abuse conditions.Benefiting from smart responsive materials and novel structural design,the safety of LIBs can be improved a lot.We expect to provide a comprehensive reference for the development of smart and safe lithium-based battery materials.

Empowering the Future: Exploring the Construction and Characteristics of Lithium-Ion Batteries

Lithium element has attracted remarkable attraction for energy storage devices, over the past 30 years. Lithium is a light element and exhibits the low atomic number 3, just after hydrogen and helium in the periodic table. The lithium atom has a strong tendency to release one electron and constitute a positive charge, as Li . Initially, lithium metal was employed as a negative electrode, which released electrons. However, it was observed that its structure changed after the repetition of charge-discharge cycles. To remedy this, the cathode mainly consisted of layer metal oxide and olive, e.g., cobalt oxide, LiFePO4, etc., along with some contents of lithium, while the anode was assembled by graphite and silicon, etc. Moreover, the electrolyte was prepared using the lithium salt in a suitable solvent to attain a greater concentration of lithium ions. Owing to the lithium ions’ role, the battery’s name was mentioned as a lithium-ion battery. Herein, the presented work describes the working and operational mechanism of the lithium-ion battery. Further, the lithium-ion batteries’ general view and future prospects have also been elaborated.

Recovery of valuable metals from spent lithium ion batteries by smelting reduction process based on FeO-SiO_2-Al_2O_3 slag system

NA novel smelting reduction process based on FeO-SiO2-Al2O3 slag system for spent lithium ion batteries with Al cans was developed, while using copper slag as the only slag former. The feasibility of the process and the mechanism of copper loss in slag were investigated. 98.83% Co, 98.39% Ni and 93.57% Cu were recovered under the optimum conditions of slag former/battery mass ratio of 4.0：1, smelting temperature of 1723 K, and smelting mass ratio of time of 30 min. The FeO-SiO2-Al2O3 slag system for the smelting process is appropriate under the conditions of m（FeO）：m（SiO2）=0.58：1？1.03：1, and 17.19%？21.52% Al2O3 content. The obtained alloy was mainly composed of Fe-Co-Cu-Ni solid solution including small amounts of matte. The obtained slag mainly consisted of fayalite and hercynite. Meanwhile, the mechanism of copper loss is the mechanical entrainment from strip-like fayalite particles in the main form of copper sulfide and metallic copper.

Effects of synthesis conditions on layered Li[Ni_(1/3)Co_(1/3)Mn_(1/3)]O_2 positive-electrode via hydroxide co-precipitation method for lithium-ion batteries

Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O2 materials was studied.It is found that when the molar ratio of ammonia to total transition-metal cations is 2.7：1,uniform particle size distribution of the complex metal hydroxide is observed via scanning electron microscopy.The average particle size of Li[Ni1/3Co1/3Mn1/3]O2 materials was measured to be about 500 nm,and the tap-density was measured to be approximately 2.37 g/cm3,which is comparable with that of commercialized LiCoO2.XRD analysis indicates that the presently synthesized Li[Ni1/3Co1/3Mn1/3]O2 has a hexagonal layered-structure.The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 positive-electrode material is determined to be 181.5 mA·h/g using a Li/Li[Ni1/3Co1/3Mn1/3]O2 cell operated at 0.1C in the voltage range of 2.8-4.5 V.The discharge capacity at the 50th cycle at 0.5C is 170.6 mA·h/g.

Preparation of uniform flower-like CuO and flower-like CuO/graphene composite and their application in lithium ion batteries

Flower-like CuO and flower-like CuO/graphene composite were prepared successfully by hydrothermal method. They were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, temperature-programmed reduction, and thermogravimetric analysis. It is found that the flower-like CuO microspheres, which are composed of CuO nanosheets, possess an average diameter of 4.2 μm and a Brunauer–Emmett–Teller surface area of 12.6 m2/g. Compared with the flower-like CuO, the obtained flower-like CuO/graphene composite shows an enhanced electrochemical performance with a higher capacity of 603 mA-h/g at 0.1 C rate and 382 mA-h/g at 1 C rate, and exhibits a better cycle stability with a high capacity retention of 95.5 % after 50 cycles even though at 1 C rate.

Synthesis of one-dimensional carbon nanostructures and their application as anode materials in lithium ion batteries

An efficient synthesis of carbon nanofibers by pyrolysis of as-prepared polypyrrole nanowires was reported. Under the subsequent KOH activation, a significant morphology variation was detected and the obtained sample took on a ribbon-like structure. The morphology and structure of the carbon nanofibers and carbon nanoribbons were characterized. When the as-prepared one-dimensional carbon nanostructures were used as anode materials in lithium ion batteries, both of them exhibited superior cyclical stability and good rate properties. After 50 cycles, the reversible capacity of carbon nanofibers electrode maintained 530 mA·h/g. Concerning carbon nanoribbons, the reversible capacity is always larger than 850 mA·h/g and the reversible capacity retention after 23 cycles is 86%.

Effect of Mn-doping on performance of Li_3V_2(PO_4)_3/C cathode material for lithium ion batteries

Li3V2-2/3xMnx（PO4）3（0≤x≤0.12） powders were synthesized by sol-gel method. The effect of Mn2＋-doping on the structure and electrochemical performances of Li3V2（PO4）3/C was characterized by XRD, SEM, XPS, galvanostatic charge /discharge and electrochemical impedance spectroscopy（EIS）. The XRD study shows that a small amount of Mn2＋-doped does not alter the structure of Li3V2（PO4）3/C materials, and all Mn2＋-doped samples are of pure single phase with a monoclinic structure （space group P21/n）. The XPS analysis indicates that valences state of V and Mn are ＋3 and ＋2 in Li3V1.94Mn0.09（PO4）3/C, respectively, and the citric acid in raw materials was decomposed into carbon during calcination, and residual carbon exists in Li3V1.94Mn0.09（PO4）/C. The results of electrochemical measurements show that Mn2＋-doping can improve the cyclic stability and rate performance of these cathode materials. The Li3V1.94Mn0.09（PO4）3/C cathode material shows the best cyclic stability and rate performance. For example, at the discharge current density of 40 mA/g, after 100 cycles, the discharge capacity of Li3V1.94Mn0.09（PO4）3/C declines from initial 158.8 mA·h/g to 120.5 mA·h/g with a capacity retention of 75.9%; however, that of the Mn-undoed sample declines from 164.2 mA·h/g to 72.6 mA·h/g with a capacity retention of 44.2%. When the discharge current is increased up to 1C, the intial discharge capacity of Li3V1.94Mn0.09（PO4）3/C still reaches 146.4 mA·h/g, and the discharge capacity maintains at 107.5 mA·h/g after 100 cycles. The EIS measurement indicates that Mn2＋-doping with a appropriate amount of Mn2＋ decreases the charge transfer resistance, which is favorable for the insertion/extraction of Li＋.

Design of multifunctional polymeric binders in silicon anodes for lithium‐ion batteries

Silicon(Si)is a promising anode material for lithium‐ion batteries(LIBs)owing to its tremendously high theoretical storage capacity(4200 mAh g−1),which has the potential to elevate the energy of LIBs.However,Si anodes exhibit severe volume change during lithiation/delithiation processes,resulting in anode pulverization and delamination with detrimental growth of solid electrolyte interface layers.As a result,the cycling stability of Si anodes is insufficient for commercialization in LIBs.Polymeric binders can play critical roles in Si anodes by affecting their cycling stability,although they occupy a small portion of the electrodes.This review introduces crucial factors influencing polymeric binders'properties and the electrochemical performance of Si anodes.In particular,we emphasize the structure–property relationships of binders in the context of molecular design strategy,functional groups,types of interactions,and functionalities of binders.Furthermore,binders with additional functionalities,such as electrical conductivity and self‐healability,are extensively discussed,with an emphasis on the binder design principle.

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.

Working Condition Real-Time Monitoring Model of Lithium Ion Batteries Based on Distributed Parameter System and Single Particle Model

Lithium ion batteries are complicated distributed parameter systems that can be described preferably by partial differential equations and a field theory. To reduce the solution difficulty and the calculation amount, if a distributed parameter system is described by ordinary differential equations （ODE） during the analysis and the design of distributed parameter system, the reliability of the system description will be reduced, and the systemic errors will be introduced. Studies on working condition real-time monitoring can improve the security because the rechargeable LIBs are widely used in many electronic systems and electromechanical equipment. Single particle model （SPM） is the simplification of LIB under some approximations, and can estimate the working parameters of a LIB at the faster simulation speed. A LIB modelling algorithm based on PDEs and SPM is proposed to monitor the working condition of LIBs in real time. Although the lithium ion concentration is an unmeasurable distributed parameter in the anode of LIB, the working condition monitoring model can track the real time lithium ion concentration in the anode of LIB, and calculate the residual which is the difference between the ideal data and the measured data. A fault alarm can be triggered when the residual is beyond the preset threshold. A simulation example verifies that the effectiveness and the accuracy of the working condition real-time monitoring model of LIB based on PDEs and SPM.

Regulating the non-effective carriers transport for high-performance lithium metal batteries

The absence of control over carriers transport during electrochemical cycling,accompanied by the deterioration of the solid electrolyte interphase(SEI)and the growth of lithium dendrites,has hindered the development of lithium metal batteries.Herein,a separator complexion consisting of polyacrylonitrile(PAN)nanofiber and MIL-101(Cr)particles prepared by electrospinning is proposed to bind the anions from the electrolyte utilizing abundant effective open metal sites in the MIL-101(Cr)particles to modulate the transport of non-effective carriers.The binding effect of the PANM separator promotes uniform lithium metal deposition and enhances the stability of the SEI layer and long cycling stability of ultra-high nickel layered oxide cathodes.Taking PANM as the Li||NCM96 separator enables high-voltage cycling stability,maintaining 72%capacity retention after 800 cycles at a charging and discharging rate of 0.2 C at a cut-off voltage of 4.5 V and 0°C.Meanwhile,the excellent high-rate performance delivers a specific capacity of 156.3 mA h g^(-1) at 10 C.In addition,outstanding cycling performance is realized from−20 to 60°C.The separator engineering facilitates the electrochemical performance of lithium metal batteries and enlightens a facile and promising strategy to develop fast charge/discharge over a wide range of temperatures.

Silicon/flake graphite/carbon anode materials prepared with different dispersants by spray-drying method for lithium ion batteries

Silicon/flake graphite/carbon （Si/FG/C） composites were synthesized with different dispersants via spray drying and subsequent pyrolysis, and effects of dispersants on the characteristics of the composites were investigated. The structure and properties of the composites were determined by X-ray diffractometry （XRD）, scanning electron microscopy （SEM） and electrochemical measurements. The results show that samples have silicon/flake graphite/amorphous carbon composite structure, good spherical appearances, and better electrochemical performance than pure nano-Si and FG/C composites. Compared with the Si/FG/C composite using washing powder as dispersant, the Si/FG/C composite using sodium dodecyl benzene sulfonate （SDBS） as dispersant has better electrochemical performance with a reversible capacity of 602.68 mA·h/g, and a capacity retention ratio of 91.58 % after 20 cycles.

Electrochemical performance of a nickel-rich LiNi0.6Co0.2Mn0.2O2 cathode material for lithium-ion batteries under different cut-off voltages

A spherical-like Ni0.6Co0.2Mn0.2(OH)2precursor was tuned homogeneously to synthesize LiNi0.6Co0.2Mn0.2O2as a cathode material for lithium-ion batteries. The effects of calcination temperature on the crystal structure, morphology, and the electrochemical performance of the as-prepared LiNi0.6Co0.2Mn0.2O2were investigated in detail. The as-prepared material was characterized by X-ray diffraction, scanning electron microscopy, laser particle size analysis, charge–discharge tests, and cyclic voltammetry measurements. The results show that the spherical-like LiNi0.6Co0.2Mn0.2O2material obtained by calcination at 900°C displayed the most significant layered structure among samples calcined at various temperatures, with a particle size of approximately 10 μm. It delivered an initial discharge capacity of 189.2 mAh•g−1at 0.2C with a capacity retention of 94.0% after 100 cycles between 2.7 and 4.3 V. The as-prepared cathode material also exhibited good rate performance, with a discharge capacity of 119.6 mAh•g−1at 5C. Furthermore, within the cut-off voltage ranges from 2.7 to 4.3, 4.4, and 4.5 V, the initial discharge capacities of the calcined samples were 170.7, 180.9, and 192.8 mAh•g−1, respectively, at a rate of 1C. The corresponding retentions were 86.8%, 80.3%, and 74.4% after 200 cycles, respectively. © 2017, University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg.

Preparation and electrochemical properties of Y-doped Li_3V_2(PO_4)_3 cathode materials for lithium batteries

Y-doped Li3V2（PO4）3 cathode materials were prepared by a carbothermal reduction（CTR） process.The properties of the Y-doped Li3V2（PO4）3 were investigated by X-ray diffraction（XRD） and electrochemical measurements.XRD studies showed that the Y-doped Li3V2（PO4）3 had the same monoclinic structure as the undoped Li3V2（PO4）3.The Y-doped Li3V2（PO4）3 samples were investigated on the Li extraction/insertion performances through charge/discharge, cyclic voltammogram（CV）, and electrochemical impedance spectra（EIS）.The optimal doping content of Y was x=0.03 in Li3V2-xYx（PO4）3 system.The Y-doped Li3V2（PO4）3 samples showed a better cyclic ability.The electrode reaction reversibility was enhanced, and the charge transfer resistance was decreased through the Y-doping.The improved electrochemical perormances of the Y-doped Li3V2（PO4）3 cathode materials were attributed to the addition of Y3＋ ion by stabilizing the monoclinic structure.

Rare Earth Elements-Doped LiCoO_2 Cathode Material for Lithium-Ion Batteries

Some compounds of LiCo 1- x RE x O 2 (RE=rare earth elements and x =0.01～0.03) were prepared by doping rare earth elements to LiCoO 2 via solid state synthesis. The microstructure characteristics of the LiCo 1- x RE x O 2 were investigated by XRD. It was found that the lattice parameters c are increased and the lattice volumes are enlarged compared to that of LiCoO 2. Moreover, the performance of LiCo 1- x RE x O 2 as the cathode material in lithium ion battery is improved, especially LiCo 1- x Y x O 2 and LiCo 1- x La x O 2. The initial charge/discharge capacities of LiCo 0.99 Y 0.01 O 2 and LiCo 0.99 La 0.01 O 2 are 174/154 (mAh·g -1 ) and 159/149 (mAh·g -1 ) respectively, while those for LiCoO 2 working in the same way are only 139/131 (mAh·g -1 ).

Porous nanostructured ZnCo2O4 derived from MOF-74:High-performance anode materials for lithium ion batteries

Nanostructured metal oxides derived from metal organic frameworks have been shown to be promising materials for application in high energy density lithium ion batteries. In this work, porous nanostructured ZnCo2O4and Co3O4were synthesized by a facile and cost-effective approach via the calcination of MOF-74 precursors and tested as anode materials for lithium ion batteries. Compared with Co3O4, the electrochemical properties of the obtained porous nanostructured ZnCo2O4exhibit higher specific capacity, more excellent cycling stability and better rate capability. It demonstrates a reversible capacity of 1243.2 m Ah/g after 80 cycles at 100 m A/g and an excellent rate performance with high average discharge specific capacities of 1586.8, 994.6, 759.6 and 509.2 m Ah/g at 200, 400, 600 and 800 m A/g, respectively.The satisfactory electrochemical performances suggest that this porous nanostructured ZnCo2O4is potentially promising for application as an efficient anode material for lithium ion batteries.

A ternary phased SnO_2-Fe_2O_3/SWCNTs nanocomposite as a high performance anode material for lithium ion batteries

A new SnO2-Fe2O3/SWCNTs（single-walled carbon nanotubes） ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO2 and Fe2O3 nanoparticles（NPs） were homogeneously located on the surface of SWCNTs,as confirmed by X-ray diffraction（XRD）,transmission electron microscope（TEM） and energy dispersive X-ray spectroscopy（EDX）.Due to the synergistic effect of different components,the as synthesized SnO2-Fe2O3/SWCNTs composite as an anode material for lithium-ion batteries exhibited excellent electrochemical performance with a high capacity of 692 mAh·g-1 which could be maintained after 50 cycles at 200 mA·g-1.Even at a high rate of2000 mA·g-1,the capacity was still remained at 656 mAh·g-1.

γ-Ray Irradiation-Derived MnO/rGO Composites for High Performance Lithium Ion Batteries

We report a γ-ray irradiation reduction method to prepare MnO/reduced graphene oxide （rCO） nanocomposite for the anode of lithium ion batteries. γ-Ray irradiation provides a clean way to generate homogeneously dispersed MnO nanoparticles with finely tuned size on rGO surface without the use of surfactant. The MnO/rGO composite enables a fully charge/discharge in 2 min to gain a reversible specific capacity of 546 （mA-h）/g which is 45 higher than the theoretical value of commercial graphite anode.

Preparation of anatase TiO_2 with assistance of surfactant OP-10 and its electrochemical properties as an anode material for lithium ion batteries

With the assistance of nonionic surfactant （OP-10） and surface-selective surfactant （CH3COOH）, anatase TiO2 was prepared as an anode material for lithium ion batteries. The morphology, the crystal structure, and the electrochemical properties of the prepared anatase TiO2 were characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, electrochemical impedance spectroscopy （EIS）, and galvanostatic charge and discharge test. The result shows that the prepared anatase TiO2 has high discharge capacity and good cyclic stability. The maximum discharge capacity is 313 mAh.g^-1, and there is no significant capacity decay from the second cycle.