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Full atomistic molecular dynamics simulations are performed on tetra-sulfides and undoped conjugated polymers pernigraniline base polyaniline (PNB), leucoemeraldine base polyaniline (LEB), poly (3,4-ethylenedioxythiophene) (PEDOT) and polypyrrole (PPY) to investigate the binding effectiveness between polysulfides and polymer binders. The weight ratio between sulfur and binder in lithium–sulfur cells is considered in 1:1 v/v mixture of dioxolane/dimethoxyethane. The simulations reveal that the end group 2 of PNB can effectively bind a lithium tetra-sulfide (i.e. Li 2 S 4) cluster or 2 out of 43 Li 2 S 4 molecules with the effect of solvent. However, repeat units of PNB, LEB, PEDOT and PPY seem ineffective in binding solvated Li 2 S 4 through non-bonded interaction, especially when the concentration of tetra-sulfide/binder in a local domain of the cathode is low. Therefore, polymers with this specific functional group (i.e. the end group 2 of PNB) are suggested to be further studied as potential effective binders to inhibit the shuttle effect of solvated lithium polysulfides. Also, since the solvent has considerable impact on the binding effectiveness between tetra-sulfides and binder, it is suggested to take advantage of the explicit solvation models, such as those built in this work, to predict how other influencing factors affect binding between polysulfides and polymers. Image 1 • Explicit solvation models have been employed to consider the solvent environment. • The weight ratio between sulfur and binder in Li–S cells has been considered. • The end group 2 of PNB can effectively bind a Li 2 S 4 cluster in the solvent. • Polymers with this specific functional group are potential effective binders. [ABSTRACT FROM AUTHOR]

Silicon monoxide (SiO) is considered an attractive alternative to conventional graphite anodes due to its high specific capacity and good cycling performance. However, it suffers from low initial Coulombic efficiency (ICE) due to a large irreversible capacity and large volume change during cycling. Both deficiencies hinder the commercial use of SiO anodes. A new organolithium compound (Li−9,9-dimethyl-9H-fluorene−tetrahydrofuran) with lower redox potential is reported to prelithiate a SiO-based anode. An SEI layer is formed during prelithiation and a controllable amount of reversible lithium is preloaded into the SiO electrode. The ICE of a prelithiated SiO-based electrode in half-cell format is increased greatly to ~90.7%. When matched with a LiNi 0·6 Co 0·2 Mn 0·2 O 2 cathode, the full cell with the prelithiated SiO/G anode exhibits a much improved ICE in comparison with the pristine one (87.1% vs. 61.1%). This facile prelithiation method is proved to be a practical solution for the commercial application of SiO-based materials. Image 1 • A novel chemical prelithiation compound was reported. • The anode with 50% Si can reach 91% ICE in a half cell and 87% in a full cell. • The prelithiation can be integrated in the existing Li-ion production. [ABSTRACT FROM AUTHOR]

Abstract: Using the anion receptor tris(penftafluorophenyl) borane as an additive to non-aqueous electrolytes, the solubility of solid Li2O2 can be dramatically increased through the Lewis acid–base interaction between boron and peroxide. The complexed boron-peroxide ions can be electrochemically oxidized with much better kinetics than the oxidation of solid Li2O2 on a carbon powder microelectrode. This discovery could lead to a new avenue for the development of high capacity, high rate, rechargeable, Li–Air batteries. [Copyright &y& Elsevier]

In this report, we study the impact of the solid electrolyte interphase (SEI) of lithium ion batteries (LIB) on low temperature performance in 3-electrode pouch cells with electrochemical impedance spectroscopy. Two kinds of electrolytes are used for the comparison purpose. One is chosen as the best low temperature electrolyte (1.0 M LiPF 6 in ethylene carbonate (EC)/ethyl methyl carbonate (EMC)/dimethyl carbonate (DMC) at a certain ratio) developed in our laboratory by design of experiment method. The other electrolyte used is state-of-art baseline electrolyte (1.0 M LiPF 6 in 3 EC/7 EMC). Electrochemical impedance of cathode, anode and the complete cell is measured in various states of aging, charge, and temperature conditions. Our results show that majority of the full cell impedance arises from anode SEI. Cathode SEI has very small impedance. Approximately 75% of full cell impedance is from anode and rest is from cathode. The impedance data are fitted by RC equivalent circuit model to extract various parameters of interfacial phenomena. Also, the data are analyzed by using the relation between the impedance, its distribution of relaxation times (DRT), and the time constants. Conclusively, the high rate performance of a LIB in low temperature depends on the kinetics of the electrochemical process rather than the value of polarization resistance. [ABSTRACT FROM AUTHOR]

Given that both elemental sulfur (S 8 ) and lithium sulfide (Li 2 S) exhibit insulating properties, the involvement of conductive host materials becomes crucial for facilitating charge transfer in sulfur cathodes within lithium-sulfur (Li-S) batteries. Furthermore, there has been a recent surge in the exploration of host materials for sulfur cathodes to address the "polysulfide shuttle" effect. This effect arises from the formation of polysulfide species during the charge-discharge cycles of the Li-S batteries and can be mitigated through physical or chemical interactions with specific materials. To qualitatively and accurately assess the interactions between polysulfides and the potential host materials, this study utilized a well-established high-performance liquid chromatography method for polysulfide analysis. The objective was to monitor the changes in polysulfide solutions after contact with 44 different carbon and inorganic materials. Based on both qualitative and quantitative chromatographic results, it was determined that 20 out of the 44 materials exhibit significant interactions with polysulfides. The primary form of interaction observed is the irreversible disproportionation reaction with elemental sulfur being one of the resulting products.

A rechargeable aqueous hybrid ion alkaline battery, using a proton and a potassium ion as charge carriers for the anode and cathode, respectively, is proposed in this study by using well-developed potassium nickel hexacyanoferrate as the cathode material and mesoporous carbon sheets as the anode material, respectively. The constructed battery operates in a concentrated KOH solution, in which the energy storage mechanism for potassium nickel hexacyanoferrate involves the redox reaction of Fe 2+ /Fe 3+ associated with potassium ion insertion/extraction and the redox reaction of Ni(OH) 2 /NiOOH. The mechanism for the carbon anode is electrochemical hydrogen storage. The cathode made of potassium nickel hexacyanoferrate exhibits both an ultrahigh capacity of 232.7 mAh g -1 under 100 mA g -1 and a consistent performance of 214 mAh g -1 at 2000 mA g -1 (with a capacity retention of 92.8% after 200 cycles). The mesoporous carbon sheet anode exhibits a capacity of 87.6 mAh·g -1 at 100 mA g -1 with a good rate and cyclic performance. The full cell provides an operational voltage of 1.55 V, a capacity of 93.6 mAh g -1 at 100 mA g -1 , and 82.4% capacity retention after 1000 cycles at 2000 mA g -1 along with a low self-discharge rate. The investigation and discussion about the energy storage mechanisms for both electrode materials are also provided.

A long cycle-life Li-S battery (both the coin cell and pouch cell) is reported with minimum shuttle effect. The performance was achieved with a bifunctional carbon material with three unique features. The carbon can catalyze the disproportionation of dissolved long-chain polysulfide ions to elemental sulfur; the carbon can ensure homogeneous precipitation of Li sulfide on the host carbon, and the carbon has a honeycomb porous structure, which can store sulfur better. All the features are demonstrated experimentally and reported in this paper. Few dissolved polysulfides are found by high-performance liquid chromatography in the electrolyte of the Li-S batteries during cycling, and only dissolved elemental sulfur is detected. The unique porous structure of the carbon made from raw silk is revealed by scanning electron microscopy. The N-containing functionalities that were introduced to carbon from the amino acids of raw silk can catalyze the disproportionation of the dissolved S n 2- to solid S 8 at the cathode side, thereby mitigating the shuttle effect. In addition, the hierarchical honeycomb porous structures generated by a carbonization process can physically trap high-order lithium polysulfides and sustain the volume change of sulfur. With the synergistic effects of the unique structures and characteristics of the carbon prepared at 800 °C, the sulfur/carbon composite delivers a high reversible capacity of over 1000 mAh g -1 after 100 cycles with a sulfur content of 1.2 mg cm -2 in a pouch cell.

Recycling spent lithium iron phosphate (LFP) cathodes in an economically sustainable way remains a great challenge due to their low-value elemental composition. Thus, both low-cost technology together with a high-value product are critical for the recovery of the LFP materials. In this study, the commercially mature ion-exchange (IX) method was explored to recover Li from LFP material for the first time. The feasibility of Li-H and Li-K IX reactions using strong and weak acid cation exchange resins was systematically investigated from the thermodynamic and kinetic perspectives. Different organic and inorganic acids were explored to obtain the feeding solution. The IX efficiency was greatly affected by the pH of the feeding solutions. Oxalic acid leaching solution with mild pH value and low iron impurity were determined to be the optimal feeding solution for IX reaction. The kinetics of IX and regeneration reaction were fast, and the resins can be reused several times without loss of IX capacity. Along with the P element remaining in the leaching solution, the Li-K IX reaction delivered a potential product of multi-elemental fertilizer. This simple and economical technology provides a practical recycling strategy for the spent LFP batteries., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The ever-growing market of portable electronics and electric vehicles has spurred extensive research for advanced lithium-ion batteries (LIBs) with high energy density. High-capacity alloy- and conversion-type anodes are explored to replace the conventional graphite anode. However, one common issue plaguing these anodes is the large initial capacity loss caused by the solid electrolyte interface formation and other irreversible parasitic reactions, which decrease the total energy density and prevent further market integration. Prelithiation becomes indispensable to compensate for the initial capacity loss, enhance the full cell cycling performance, and bridge the gap between laboratory studies and the practical requirements of advanced LIBs. This review summarizes the various emerging anode and cathode prelithiation techniques, the key barriers, and the corresponding strategies for manufacturing-compatible and scalable prelithiation. Furthermore, prelithiation as the primary Li + donor enables the safe assembly of new-configured "beyond LIBs" (e.g., Li-ion/S and Li-ion/O 2 batteries) and high power-density Li-ion capacitors (LICs). The related progress is also summarized. Finally, perspectives are suggested on the future trend of prelithiation techniques to propel the commercialization of advanced LIBs/LICs., (© 2022 Wiley-VCH GmbH.)

The high temperature cycling performance of a wide temperature electrolyte and the solid electrolyte interphase (SEI) along the cycling were investigated using a three-electrode pouch cell. The electrolyte developed in our lab demonstrated outstanding low temperature performance. The electrolyte was found to have a good and stable cycling performance at a high temperature in comparison with a state-of-the-art baseline electrolyte. Electrochemical impedance spectroscopy (EIS) was conducted on the anode, the cathode and the full cell independently with a reference embedded pouch cell. The distribution of relaxation times (DRT) transformation was calculated from the EIS spectrum. An equivalent circuit model was used to fit the anode EIS data and the electrochemical process on the anode was revealed. We concluded that a denser SEI layer was built on the anode of the improved electrolyte., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Rechargeable lithium-ion batteries have built much of our modern society. Developing high-loading and high-energy batteries have become an inevitable trend to satisfy the ever-growing demand of energy consumption. However, issues related to mechanical instability and electrochemical polarization have become more prominent accompanying the increase of electrode thickness. How to establish a robust and rapid charge transport network within the electrode architecture plays a vital role for the mechanical property and the reaction dynamics of thick electrodes. In this review, principles of charge transport mechanism and challenges of thick electrode development are elaborated. Next, recent progress on advanced electrode architecture design focused on structural engineering is summarized. Finally, a transmission line model is proposed as an effective tool to guide the engineering of thick electrodes., (© 2021 Wiley-VCH GmbH.)

Organic electrode materials have been considered as promising candidates for the next generation rechargeable battery systems due to their high theoretical capacity, versatility, and environmentally friendly nature. Among them, organosulfur compounds have been receiving more attention in conjunction with the development of lithium-sulfur batteries. Usually, organosulfide electrodes can deliver a relatively high theoretical capacity based on reversible breakage and formation of disulfide (S-S) bonds. In this review, we provide an overview of organosulfur materials for rechargeable lithium batteries, including their molecular structural design, structure related electrochemical performance study and electrochemical performance optimization. In addition, recent progress of advanced characterization techniques for investigation of the structure and lithium storage mechanism of organosulfur electrodes are elaborated. To further understand the perspective application, the additive effect of organosulfur compounds for lithium metal anodes, sulfur cathodes and high voltage inorganic cathode materials are reviewed with typical examples. Finally, some remaining challenges and perspectives of the organosulfur compounds as lithium battery components are also discussed. This review is intended to serve as general guidance for researchers to facilitate the development of organosulfur compounds.

Overcharge abuse can trigger thermal runaway when a device is left unattended. Redox shuttles, as economic and efficient electrolyte additives, have been proven to provide reliable and reversible protection for state-of-art Li-ion batteries (LIBs) against overcharge. Here, a functional organic salt, trisaminocyclopropenium perchlorate (TAC•ClO 4 ), is developed and employed as a redox shuttle for overcharge protection in a Na-ion battery system. This type of novel redox shuttle molecule is reported for the first time. As a unique ionic compound with the smallest aromatic ring structure, TAC•ClO 4 exhibits distinctive attributes of fast diffusion, high solubility, and ultrahigh chemical/electrochemical stability in both redox states. With merely 0.1 M TAC•ClO 4 in electrolyte, Na 3 V 2 (PO 4 ) 3 cathode can carry overcharge current even up to 10C or 400% SOC. Na 3 V 2 (PO 4 ) 3 /hard carbon cells demonstrated strong anti-overcharging ability of 176 cycles at 0.5C rate and 54 cycles at 1C rate with 100% overcharge. Moreover, TAC•ClO 4 addition has little impact on the electrochemical performance of Na-ion batteries, especially on the rate performance and the initial Columbic efficiency. Interestingly, a unique and reversible electrochromic behavior of TAC•ClO 4 electrolyte can promptly provide the device an overcharge alarm under a designed potential to further enhance the safety level.

SnO 2 is an attractive anodic material for advanced lithium-ion batteries (LIBs). However, its low electronic conductivity and large volume change in lithiation/delithiation lead to a poor rate/cycling performance. Moreover, the initial Coulombic efficiencies (CEs) of SnO 2 anodes are usually too low to build practical full LIBs. Herein, a two-step hydrothermal synthesis and pyrolysis method is used to prepare a SnO 2 /C nanocomposite, in which aggregated SnO 2 nanosheets and a carbon network are well-interpenetrated with each other. The SnO 2 /C nanocomposite exhibits a good rate/cycling performance in half-cell tests but still shows a low initial CE of 45%. To overcome this shortage and realize its application in a full-cell assembly, the SnO 2 /C anode is controllably prelithiated by the lithium-biphenyl reagent and then coupled with a LiCoO 2 cathode. The resulting full LIB displays a high capacity of over 98 mAh g -1 LCO in 300 cycles at 1 C rate.

Lithium-rich layered oxides are promising cathode candidates for the production of high-energy and high-power electronic devices with high specific capacity and high discharge voltage. However, unstable cycling performance, especially at high charge-recharge rate, is the most challenge issue which needs to be solved to foster the diffusion of these materials. In this paper, hierarchical platelike Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 cathode materials were synthesized by a facile solvothermal method followed by calcination. Calcination time was found to be a key parameter to obtain pure layered oxide phase and tailor its hierarchical morphology. The Li-rich material consists of primary nanoparticles with exposed {010} planes assembled to form platelike layers which exhibit low resistance to Li + diffusion. In detail, the product by calcination at 900 °C for 12 h exhibits specific capacity of 228, 218, and 204 mA h g -1 at 200, 400, and 1000 mA g -1 , respectively, whereas after 100 cycles at 1000 mA g -1 rate of charge and recharge the specific capacity was retained by about 91%.

Tris(pentafluorophenyl)borane (TPFPB) was found to be an efficient catalyst for rapid superoxide (O2(-)) disproportionation. The kinetics for the catalytic disproportionation reaction is much faster than the reaction between O2(-) and propylene carbonate. Therefore, the negative impact of the reaction between the electrolyte and O2(-) produced by the O2 reduction is minimized. The cathodic current for O2 reduction can be doubled in the presence of TPFPB. The high reduction current resulted from the pseudo two-electron O2-reduction reaction due to the replenishment of O2 at the electrode surface. This discovery could lead to a new avenue for the development of high-capacity, high-rate, rechargeable Li-air batteries., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A mixed nonaqueous electrolyte that contains acetonitrile and propylene carbonate (PC) was found to be suitable for a Li-O(2) battery with a metallic Li anode. Both the concentration and diffusion coefficient for the dissolved O(2) are significantly higher in the mixed electrolyte than those in the pure PC electrolyte. A powder microelectrode was used to investigate the O(2) solubility and diffusion coefficient. A 10 mA cm(-2) discharge rate on a gas-diffusion electrode is demonstrated by using the mixed electrolyte in a Li-O(2) cell., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Hydrogen physisorption in different carbonaceous materials was investigated in liquid nitrogen (77 K). The total hydrogen adsorption was found to have a linear relationship with the surface area of pores <30 A. The surface area and porosity of the carbon materials were determined by dinitrogen adsorption at 77 K and density function theory (DFT). The active sites for hydrogen adsorption were investigated and found to be related to the edge orientation of defective graphene micro-sheet domains.