A Review:Pre-lithiation Strategies Based on Cathode Sacrificial Lithium Salts for Lithium-Ion Capacitors

Similar to lithium-ion batteries(LIBs),during the first charge/discharge process of lithium-ion capacitors(LICs),lithium-intercalated anodes(e.g.,silicon,graphite,and hard carbon)also exhibit irreversible lithium intercalation behaviors,such as the formation of a solid electrolyte interface(SEI),which will consume Li^(+)in the electrolyte and significantly reduce the electrochemical performance of the system.Therefore,pre-lithiation is an indispensable procedure for LICs.At present,commercial LICs mostly use lithium metal as the lithium source to compensate for the irreversible capacity loss,which has the demerits of operational complexity and danger.However,the pre-lithiation strategy based on cathode sacrificial lithium salts(CSLSs)has been proposed,which has the advantages of low cost,simple operation,environmental protection,and safety.Therefore,there is an urgent need for a timely and comprehensive summary of the application of CSLSs to LICs.In this review,the important roles of pre-lithiation in LICs are detailed,and different pre-lithiation methods are reviewed and compared systematically and comprehensively.After that,we systematically discuss the pre-lithiation strategies based on CSLSs and mainly introduce the lithium extraction mechanism of CSLSs and the influence of intrinsic characteristics and doping amount of CSLSs on LICs performance.In addition,a summary and outlook are conducted,aiming to provide the essential basic knowledge and guidance for developing a new pre-lithiation technology.

Synthesis and Structural Characterizations of a New Lithium Salt for Lithium-ion Batteries

A novel crystal [（CH3O）2CO]3Li2[C2BF2O4]2 was synthesized and fully characterized by FT-IR and single-crystal X-ray diffraction analysis. It crystallizes in monoclinic system, P2Jn space group, with a = 8.1749（2）, b = 10.7449（2）, c = 12.8665（3） A, βl = 94.654（2）°, V= 1126.45（4） A3, Z = 2, Dc = 1.644 g/cm, F（000） = 568, p = 1.498 mm^-1, Mr= 557.77 g/mol, the final R = 0.0334 and wR = 0.0903. The structure analysis revealed that each Li atom is three-coordinated and adopts 1.5 O atoms of two different dimethyl carbonates and one O atom of C2BF2O4-. Thermal stability and infrared spectra analysis were studied and discussed.

Studies on the Thermodynamics and Thermal Chemistry Properties for Lithium Salts and Their Aqueous Solution Systems

1 Introduction With the industrial development of lithium battery,nuclear and aerospace industry,the demands of metal lithium and its compounds are increasing significantly.Lithium is called as the energy of the metal in the new century(Zhang et al.2001).The total reserve of lithium resources around the world7

The Phase Diagram of Lithium Salt Systems and Its Application in Extraction of Lithium from Salt Lake Brine

At present,the extraction of lithium from salt lake brine is the new trend of the salt lake industrialization.The saltine lake lithium resources are extremely rich in western china,especially in Qinghai-Tibetan plateau.Brine of salt

Syntheses and Application of All-lithium Salts of Heteropolyacid as Electrolyte of Lithium-ion Battery

The all-lithium salts of heteropoly acid Li_xXM_ 12O_ 40(HPA-Li)(X=P, Si; M=Mo, W) were obtained via ion exchange and characterized by means of IR and UV spectroscopies, TG and elemental analyses. The conductivity of the electrolytic solution consisting of Li_3PW_ 12O_ 40 and PC/DME mixing solvent(1/2.5, volume ratio) is up to 7.2×10 -2 S/cm, being higher than that of LiClO_4 as the electrolyte. The all-lithium salts were used as electrolytes in secondary lithium-ion batteries. The discharge capacity of the PAS/Li batteries with Li_3PW_ 12O_ 40 electrolyte solutions reaches to 148 (mA·h)/g and the cyclic life is up to 380 times, much better than those of commercialized products with LiClO_4 and LiAsF_6 as electrolytes.

Would Adding Low Doses of Lithium Salts and/or Prebiotic Fibre Interventions to an Effective Exercise Protocol Further Enhance Retention of Cognitive Integrity? Potential for Preventing Loss of Cognition with Aging Using Combinations of Low Cost Regimens

It is clear that loss of cognition is becoming epidemic in our aging society. Onset of dementia and diseases such as Alzheimer’s are very prevalent and the prognosis is not optimistic that numbers will decrease in the coming decades. Thus, this epidemic is impacting the quality of life of a large number of people, primarily females, as well as the health care systems of many countries. Of relevance is the fact that large clinical trials of candidate drugs to treat these conditions have not been overwhelming successes, indicating that we may need to take new directions or focus on prevention. One conservative approach in this regard has been the use of exercise protocols to both retain cognition and inhibit progression of loss. With the optimization of exercise protocols, it may be time to step back and ask “how can these successes be augmented to further inhibit risk and stabilize loss early in the development of these conditions?” An example of how this could be approached is via supplementation with low doses of minerals such as lithium salts, or supplementation of the diet with prebiotics in patients with obesity and metabolic syndrome. Regarding the former, recent epidemiological studies have indicated that the content of Li in the drinking water is associated with lower incidences of cognitive diseases/conditions. While not definitive, such clues may warrant performing controlled studies using low doses of lithium salts plus exercise to further optimize impact on retention of cognition in those at risk, or those with early disease. Similarly, patients with obesity are at higher risk to develop dementia, and prebiotics can correct some of the metabolic derangements associated with the microbiome in such patients to impact risk. Thus, multiple low cost interventions plus exercise could further enhance retention of cognitive integrity in specific populations.

Effects of conductive agent type on lithium extraction from salt lake brine with LiFePO_(4) electrodes

Electrochemical lithium extraction from salt lakes is an effective strategy for obtaining lithium at a low cost.Nevertheless,the elevated Mg:Li ratio and the presence of numerous coexisting ions in salt lake brines give rise to challenges,such as prolonged lithium extraction periods,diminished lithium extraction efficiency,and considerable environmental pollution.In this work,Li FePO4(LFP)served as the electrode material for electrochemical lithium extraction.The conductive network in the LFP electrode was optimized by adjusting the type of conductive agent.This approach resulted in high lithium extraction efficiency and extended cycle life.When the single conductive agent of acetylene black(AB)or multiwalled carbon nanotubes(MWCNTs)was replaced with the mixed conductive agent of AB/MWCNTs,the average diffusion coefficient of Li+in the electrode increased from 2.35×10^(-9)or 1.77×10^(-9)to 4.21×10^(-9)cm^(2)·s^(-1).At the current density of 20 mA·g^(-1),the average lithium extraction capacity per gram of LFP electrode increased from 30.36 mg with the single conductive agent(AB)to 35.62 mg with the mixed conductive agent(AB/MWCNTs).When the mixed conductive agent was used,the capacity retention of the electrode after 30 cycles reached 82.9%,which was considerably higher than the capacity retention of 65.8%obtained when the single AB was utilized.Meanwhile,the electrode with mixed conductive agent of AB/MWCNTs provided good cycling performance.When the conductive agent content decreased or the loading capacity increased,the electrode containing the mixed conductive agent continued to show excellent electrochemical performance.Furthermore,a self-designed,highly efficient,continuous lithium extraction device was constructed.The electrode utilizing the AB/MWCNT mixed conductive agent maintained excellent adsorption capacity and cycling performance in this device.This work provides a new perspective for the electrochemical extraction of lithium using LFP electrodes.

Effect of the anionic composition of sulfolane based electrolytes on the performances of lithium-sulfur batteries

In lithium-sulfur batteries,cell design,specifically electrolyte design,has a key impact on the battery performance.The effect of lithium salt anion donor number(DN)(DN[PF_(6)]^(-)=2.5,DN[N(SO_(2)CF_(3))_(2)]^(-)=5.4,DN[ClO_(4)]^(-)=8.4,DN[SO_(3)CF_(3)]^(-)=16.9,and DN[NO_(3)]^(-)=21.1)on the patterns of lithium-sulfur batteries and lithium metal electrode performances with sulfola ne-based electrolytes is investigated.An increase in DN of lithium salt anions leads to an increase in the depth and rate of electrochemical reduction of sulfur and long-chain lithium polysulfides and to a decrease in those for medium-and short-chain lithium polysulfides.DN of lithium salt anions has weak effect on the discharge capacity of lithium-sulfur batteries and the Coulomb efficiency during cycling,with the exception of LiSO_(3)CF_(3)and LiNO_(3).An increase in DN of lithium salt anions leads to an increase in the cycling duration of lithium metal anodes and to a decrease in the presence of lithium polysulfides.In sulfolane solutions of LiNO_(3)and LiSO_(3)CF_(3),lithium polysulfides do not affect the cycling duration of lithium metal anodes.

Mixed salts for lithium iron phosphate-based batteries operated at wide temperature range

To achieve good performance for LiFePO4-based batteries operated at a wide temperature range,mixed salts of LiBF4 LiBOB（lithium bis（oxalato）borate） and LiTFSI（lithium bis（trifluoromethanesulfonyl）imide）-LiBOB were investigated as alternative lithium salts to LiPF6 in non-aqueous electrolytes.LiFePO4/Li half cells using LiPF6,LiBF4-LiBOB and LiTFSI-LiBOB slats as lithium salts were investigated by galvanostatic cycling,cyclic voltammetry,thermogravimetric analysis.The results show that LiBF4-LiBOB and LiTFSI-LiBOB mixed salts are much more thermally stable than LiPF6.Corrosion of Al foil in the LiTFSI-based electrolytes can be suppressed successfully by the addition of LiBOB as a co-salt.The electrochemical performance of LiBF4-LiBOB and LiTFSI-LiBOB mixed salts based cells are both better than that of LiPF6-based cell.LiTFSI-LiBOB mixed salt based electrolyte is considered to be a very promising electrolyte candidate for Li-ion batteries that will be used in wide-temperature applications.

NMR Studies on Diffusion and Molecular Motions of Imidazolium Ionic Liquids doped by Lithium Salts Related to Ionic Conductivity and Computational Interaction Energy

1 Results Room-temperature Ionic liquids (RTILs) are special class of compounds, where a combination of cations and anions produces neutral, stable and viscous liquids with high ionic conductivity. Widely spread applications are proposed to use conductors, electrolytes, clean solvents and others. Especially, RTILs are expected to be safe electrolytes in the ion-lithium batteries. In this study, NMR methods are used to clarify the basic properties of the individual movements of the anions and cations of ...

Problems of Lithium Isotope Research in Salt Lake Study

Lithium in nature mainly exists in the forms of solid minerals and ionic liquid.More than 150 lithium minerals exist,which are mainly pegmatite mineral including triphane,lithionite and petalite.Liquid lithium mainly

Highly efficient extraction of lithium from salt lake brine by LiAl-layered double hydroxides as lithium-ion-selective capturing material

The extraction of lithium from salt lake brine in the Chinese Qaidam Basin is challenging due to its high Mg/Li and Na/Li ratios. Herein, we utilized a reaction-coupled separation technology to separate sodium and lithium ions from a high Na/Li ratio brine(Na/Li = 48.7, w/w) and extracted lithium with Li Al-layered double hydroxides(Li Al-LDHs). The Li Al-LDHs act as lithium-ion-selective capturing materials from multication brines. That is, the lithium ions selectively enter the solid phase to form Li Al-LDHs, and the sodium ions are still retained in the liquid phase. This is because the lithium ions can be incorporated into the structural vacancies of LiAl-LDHs, whereas the sodium ions cannot. The effects of reaction conditions on lithium loss and separation efficiency were investigated at both the nucleation and the crystallization stage, e.g., the nucleation rotating speed, the Li/Al molar ratio, the crystallization temperature and time, and co-existing cations. The lithium loss is as low as 3.93% under optimal separation conditions.The sodium ions remained in the solution. Consequently, an excellent Na/Li separation efficiency was achieved by this reaction-coupled separation technology. These findings confirm that LiAl-LDHs play a critical function in selectively capturing lithium ions from brines with a high Na/Li ratio, which is useful for the extraction of lithium ions from the abundant salt lake brine resources in China.

Concentrated dual-salt electrolytes for improving the cycling stability of lithium metal anodes

Lithium（Li） metal is an ideal anode material for rechargeable Li batteries, due to its high theoretical specific capacity（3860 mAh/g）, low density（0.534 g/cm3）, and low negative electrochemical potential（-3.040 V vs. standard hydrogen electrode）. In this work, the concentrated electrolytes with dual salts, composed of Li[N（SO2F）2]（Li FSI） and Li[N（SO2CF3）2]（Li TFSI） were studied. In this dual-salt system, the capacity retention can even be maintained at 95.7%after 100 cycles in Li｜Li FePO4 cells. A Li｜Li cell can be cycled at 0.5 mA/cm2 for more than 600 h, and a Li｜Cu cell can be cycled at 0.5 m A/cm2 for more than 200 cycles with a high average Coulombi efficiency of 99%. These results show that the concentrated dual-salt electrolytes exhibit superior electrochemical performance and would be a promising candidate for application in rechargeable Li batteries.

Lithium Ion Extraction from the High Ration Mg/Li Salt Lake Brine with Ionic Liquid in Triisobutyl Phosphate and Kerosene

1 Introduction As the lightest metal with the unique properties of energy production and storage,lithium is regarded as the new century energy metal.Lithium and its compounds were widely used in various industrial fields,especially in

LITHIUM RESOURCES IN CHINA'S SALT LAKES & ITS SUSTAINABLE DEVELOPMENT

This article gives an introductory exposition of the growing demands of lithium on the market against the background of current rapid S&Tprogress and booming economic development, the worldwide trend in the production of lithium salts and the rich lithium reserves in China’s salt lakes as well as the brilliant prospects for its exploitation in the future. The article proposes that a sustainable exploitation of the lithium trove from these salt lakes should be rooted in comprehensive utilization of the trove and take a long-term approach, emphasizing high value proliferation in developing quality lithium-based products. Also, it expresses some tentative ideas on building demonstration bases for all-round exploitation and utilization of the salt lake resources and the development of lithium cells.

Distinctive electrochemical performance of novel Fe-based Li-rich cathode material prepared by molten salt method for lithium-ion batteries

For constructing next-generation lithium-ion batteries with advanced performances,pursuit of highcapacity Li-rich cathodes has caused considerable attention.So far,the low discharge specific capacity and serious capacity fading are strangling the development of Fe-based Li-rich materials.To activate the extra-capacity of Fe-based Li-rich cathode materials,a facile molten salt method is exploited using an alkaline mixture of LiOH–LiNO3–Li2O2 in this work.The prepared Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2 material yields high discharge specific capacity and good cycling stability.The discharge specific capacity shows an upward tendency at 0.1 C.After 60 cycles,a high reversible specific capacity of ~250 m Ah g-1is delivered.The redox of Fe3+/Fe4+and Mn3+/Mn4+are gradually activated during cycling.Notably,the redox reaction of Fe2+/Fe3+can be observed reversibly below 2 V,which is quite different from the material prepared by a traditional co-precipitation method.The stable morphology of fine nanoparticles(100–300 nm)is considered benefiting for the distinctive electrochemical performances of Li1.09(Fe0.2Ni0.3Mn0.5)0.91O2.This study demonstrates that molten salt method is an inexpensive and effective approach to activate the extra capacity of Fe-based Li-rich cathode material for high-performance lithium-ion batteries.

Tuning hybrid liquid/solid electrolytes by lowering Li salt concentration for lithium batteries

Hybrid liquid/solid electrolytes（HLSEs） consisting of conventional organic liquid electrolyte（LE）, polyacrylonitrile（PAN）, and ceramic lithium ion conductor Li（1.5）Al（0.5）Ge（1.5）（PO4）3（LAGP） are proposed and investigated. The HLSE has a high ionic conductivity of over 2.25 × 10^（-3） S/cm at 25？C, and an extended electrochemical window of up to 4.8 V versus Li/Li＋. The Li｜HLSE｜Li symmetric cells and Li｜HLSE｜Li FePO4 cells exhibit small interfacial area specific resistances（ASRs） comparable to that of LE while much smaller than that of ceramic LAGP electrolyte, and excellent performance at room temperature. Bis（trifluoromethane sulfonimide） salt in HLSE significantly affects the properties and electrochemical behaviors. Side reactions can be effectively suppressed by lowering the concentration of Li salt. It is a feasible strategy for pursuing the high energy density batteries with higher safety.

溶析结晶用于盐湖卤水提钾和镁锂分离研究

采用溶析结晶法快速分离盐湖卤水中氯化钾并降低卤水中的镁锂比,解决青海盐湖盐田摊晒存在的生产周期长、需要修建大面积盐田等难题。以有机溶剂为溶析剂,考察了不同种类溶析剂加入量、溶析温度、溶析时间等对盐湖氯化钾收率及镁锂比的影响。实验结果表明,以无水乙醇为溶析剂与盐湖卤水体积比为2∶1,溶析温度为-15℃,时间为90 min时,氯化钾和氯化钠的收率分别达到93.15%和99.84%。溶析结晶后的母液经过过滤,在70~80℃,以0.5℃/min的降温速率进行动态降温,析出氯化镁晶体,镁锂质量比由原卤中的388.44降低至266.63,最终达到快速分离氯化钾的目的及为后续对镁锂进一步分离提供更有利的条件。

青藏高原盐湖硼、锂同位素变化规律及其对当雄错盐湖资源评价应用

近年,硼、锂同位素地球化学理论和分馏机理的深入,为盐湖体系硼、锂同位素示踪奠定了基础。基于现有大量研究数据,文章系统归纳盐湖体系硼、锂同位素分馏变化特征,总结盐湖演化过程硼、锂同位素组成的变化规律,建立它们的示踪方法。并以此为基础,对西藏典型富硼、锂盐湖−当雄错开展了硼同位素示踪,解决了当雄错与其物源硼同位素特征不符的难题,提出当雄错湖底蕴含大型硼、锂矿床的新认识,并预测了湖底的硼、锂资源量。根据盐湖体系硼、锂同位素地球化学特征,揭示了溶蚀湖的盐湖资源评价意义,为盐湖体系硼、锂同位素示踪和盐湖资源评价奠定理论基础。此外,借助硼同位素地球化学手段建立的当雄错“围岩−地热水−盐湖”的物源补给模式在西藏和全球具有普遍性。

富锂硫酸盐型盐湖卤水蒸发实验研究进展

随着“双碳”目标的提出,锂在新能源材料领域中的应用受到高度关注,锂的需求呈现爆发式增长。世界锂资源以矿石锂和盐湖锂为主,盐湖锂因其储量大成为未来锂资源开发的重点,因而占比最大的硫酸盐型盐湖成为焦点。因盐湖卤水组成差异较大,叠加硫酸盐型盐湖特殊属性,使得锂在盐田蒸发阶段存在多种结晶形式而造成损失,增加了锂的有效富集难度。总结了前人针对富锂硫酸盐型盐湖的蒸发实验研究结果,结合相图分析总结富锂硫酸盐型盐湖蒸发结晶析盐规律,重点关注锂的浓缩状态及析盐结晶形式,为硫酸盐型盐湖锂资源开发提供参考。