A comprehensive review of pre-lithiation/sodiation additives for Li-ion and Na-ion batteries

Lithium/Sodium-ion batteries(LIB/SIB)have attracted enormous attention as a promising electrochemical energy storage system due to their high energy density and long cycle life.One of the major hurdles is the initial irreversible capacity loss during the first few cycles owing to forming the solid electrolyte interphase layer(SEI).This process consumes a profusion of lithium/sodium,which reduces the overall energy density and cycle life.Thus,a suitable approach to compensate for the irreversible capacity loss must be developed to improve the energy density and cycle life.Pre-lithiation/sodiation is a widely accepted process to compensate for the irreversible capacity loss during the initial cycles.Various strategies such as physical,chemical,and electrochemical pre-lithiation/sodiation have been explored;however,these approaches add an extra step to the current manufacturing process.Alternative to these strategies,pre-lithiation/sodiation additives have attracted enormous attention due to their easy adaptability and compatibility with the current battery manufacturing process.In this review,we consolidate recent developments and emphasize the importance of using pre-lithiation/sodiation additives(anode and cathode)to overcome the irreversible capacity loss during the initial cycles in lithium/sodium-ion batteries.This review also addresses the technical and scientific challenges of using pre-lithiation/sodiation additives and offers the insights to boost the energy density and cycle life with their possible commercial exploration.The most important prerequisites for designing effective pre-lithiation/sodiation additives have been explored and the future directions have been discussed.

In situ tracking of the lithiation and sodiation process of disodium terephthalate as anodes for rechargeable batteries by Raman spectroscopy

Organic compounds represent an appealing group of electrode materials for rechargeable batteries due to their merits of biomass,sustainability,environmental friendliness,and processability.Disodium terephthalate(Na_(2)C_(8)H_(4)O_(4),Na_(2)TP),an organic salt with a theoretical capacity of 255 mAh·g^(-1),is electroactive towards both lithium and sodium.However,its electrochemical energy storage(EES)process has not been directly observed via in situ characterization techniques and the underlying mechanisms are still under debate.Herein,in situ Raman spectroscopy was employed to track the de/lithiation and de/sodiation processes of Na2TP.The appearance and then disappearance of the–COOLi Raman band at 1625 cm^(-1) during the de/lithiation,and the increase and then decrease of the–COONa Raman band at 1615 cm^(-1) during the de/sodiation processes of Na2TP elucidate the one-step with the 2Li+or 2Na+transfer mechanism.We also found that the inferior cycling stability of Na2TP as an anode for sodium-ion batteries(SIBs)than lithium-ion batteries(LIBs)could be due to the larger ion radium of Na+than Li+,which results in larger steric resistance and polarization during EES.The Na2TP,therefore,shows greater changes in spectra during de/sodiation than de/lithiation.We expect that our findings could provide a reference for the rational design of organic compounds for EES.

酸活化法制备钠基膨润土工艺研究

研究了由钙基膨润土通过酸活化制备钠基膨润土的工艺条件 ;对产品的物理性能进行了检测。结果表明 :经过精化、酸化和钠化处理制得的钠基膨润土 。

钠离子电池预钠化技术研究进展

钠离子电池是下一代低成本和高性能规模储能电池技术之一,预钠化技术可有效补充其在循环过程中的不可逆钠损耗,因此在钠离子电池的实际应用中具有重要地位。本工作综述了目前已有的预钠化方法,包括物理预钠化、电化学预钠化、化学反应预钠化、正极添加剂以及富钠正极。考虑各种预钠化技术安全性、可操作性、高效性和整体成本等诸多因素,分析了各种预钠化技术的优势与不足,指出了目前预钠化技术存在的问题,最后展望了预钠化技术在未来钠离子电池中的商业前景和发展方向。物理预钠化操作简单方便,但安全性是其主要问题;电化学预钠化能获得稳定的SEI膜,但受限于繁琐的工艺步骤;化学反应预钠化也能形成均匀致密的SEI膜,但对气氛有一定的要求,且溶剂昂贵;正极添加剂操作简单方便,但对其产生的残留物和气体的研究甚少;富钠正极稳定性好,但受限于种类太少。未来的预钠化研究需要综合考虑成本、环保、安全和稳定性等因素,并对副反应和副产物的影响机理进行深入地研究。

原位透射电镜研究正交相五氧化二铌纳米片的电化学储钠机制

由于正交相五氧化二铌(T-Nb_(2)O_(5))为ReO_(3)型层状结构,锂、钠离子可以在其(001)平面快速脱嵌,而在[001]方向的传输一般较难。本研究通过原位透射电子显微镜(Transmission Electron Microscope,TEM)方法研究钠在T-Nb_(2)O_(5)纳米片(001)面内及[001]方向的钠离子电化学嵌入行为,发现由于纳米片晶体存在大量的位错和畴界,钠离子可通过这些缺陷穿越(001)面扩散,并进而在深层的(001)面内快速扩散。同时,本研究还发现刚合成的T-Nb_(2)O_(5)纳米片在[001]方向上存在调制结构,存在交替分布的压应变和张应变区域,而钠离子的嵌入可以调节这些应变分布。

钠离子电池预钠化技术研究进展

介绍了钠离子电池预钠化技术的研究进展。叙述了首圈循环效率低的原因,并综述了最新正负极预钠化技术的发展情况,总结了不同类别预钠化技术的优势和不足,对预钠化技术的发展趋势进行了评述。

First-principles insight into Li and Na ion storage in graphene oxide

The structural, electronic, and adsorption properties of Li/Na ions on graphene decorated by epoxy groups are investigated by first-principles calculations based on density functional theory.Our results show that the concentration of epoxy groups remarkably affects the structural and electronic properties of graphene.The bandgaps change monotonically from0.16 eV to 3.35 eV when the O coverage increases from 12.5% to 50%(O/C ratio).Furthermore, the highest lithiation potential of 2.714 V is obtained for the case of graphene oxide(GO) with 37.5 % O coverage, while the highest sodiation potential is 1.503 V for GO with 12.5% O coverage.This clearly demonstrates that the concentration of epoxy groups has different effects on Li and Na storage in GO.Our results provide a new insight into enhancing the Li and Na storage by tuning the concentration of epoxy groups on GO.

Pomegranate-inspired porous SnSe/ZnSe@C anode:A stress-buffer nanostructure for fast and ultrastable sodium-ion storage

Tin selenide(SnSe)is considered as a potential anode for sodium-ion batteries(SIBs)owing to its high theoretical specific capacity.Unfortunately,it suffers from drastic volume expansion/contraction during sodium ions insertion/extraction,resulting in poor cycling stability.Herein,a pomegranate-inspired porous carbon shell wrapped heterogeneous SnSe/ZnSe composite(SnSe/ZnSe@C)is exquisitely designed and fabricated through electrostatic spraying followed by high-temperature selenization.The polyacrylonitrile-derived carbon shell acts as an adhesive to link the porous cubic SnSe/ZnSe and form highly interconnected microcircuits to improve the electron/ion transfer efficiency and inhibit the bulk volume change of internal metallic selenide nanoparticles and polyselenides dissolution during repeated cycling.Moreover,the abundant heterostructure interface of SnSe/ZnSe further significantly accelerates the electrons/ions transport.As a result,the as-prepared SnSe/ZnSe@C electrode exhibits a high specific capacity(508.3 m Ah g^(-1)at 0.05 A g^(-1)),excellent rate performance(177.8 m Ah g^(-1)at 10.0 A g^(-1)),and remarkable cycling stability(195.9 m Ah g^(-1)after 10,000 cycles at 5.0 A g^(-1)).Furthermore,in-situ Xray diffraction(XRD)/Raman,ex-situ transmission electron microscopy,and kinetic analysis clearly reveal a four-step electrochemical reaction process and battery-capacitor dual-mode sodium storage mechanism.This work provides a new perspective for developing commercial SIBs anode materials with high capacity and long lifespan.

钠离子化和质子化环肽类似物的碰撞裂解途径比较

近年来,环肽因其生物学功能和结构多样性受到广泛关注,但它们的结构鉴定比线性肽更困难。碰撞活化解离(CAD)质谱技术是分析环肽结构的重要手段。本工作通过电喷雾电离技术产生4种环肽类似物的钠离子化和质子化离子,并采用串联质谱进行研究。钠离子化和质子化离子的CAD谱图表现出较大差异,其中钠离子化复合物在测序方面优于质子化复合物。对于钠离子化复合物来说,钠离子与环内的主链羰基氧原子配位,其CAD谱图易于解析;而质子化复合物的CAD谱图存在多个平行的解离通道,比较复杂,并且这种复杂性与环肽类似物的官能团密切相关。结合2种复合物的CAD谱图,可以提供环肽类似物的互补信息,使其结构鉴定更加可靠。

钠离子电容器负极的双功能补钠研究

电极的首次库伦效率低是限制快充钠离子电容器规模化使用的原因之一,这主要源于电解液的不可逆分解以及电极材料造成的不可逆损失.我们选取高倍率特性的Nb_(2)O_(5)负极材料作为研究对象,采用钠萘/2-甲基-四氢呋喃作为预钠化剂,发展了一种简单且可精确调控的双功能预钠化剂,实现了预活化,获得了高稳定循环的NaxNb_(2)O_(5)电极,从而补偿了钠在材料中的不可逆吸收.研究发现,预钠化过程同时抵消了电解液分解所产生的损失,有利于在电极/电解液界面形成坚固的富含无机物的固体电解质界面膜.通过补偿Nb_(2)O_(5)负极的体相与界面的钠损失,构建了稳定且具有高能量密度的钠离子电容器.本研究为调控储钠电极的首次库伦效率及其在下一代钠离子电容器中的应用提供了新方法.