Next-generation Li-ion Batteries Research Articles

Multi-Doping Exploration of (Sb, Bi and Ba) by First Principles on Ordered Zn–Si–P Compounds as High-Performance Anodes for Next-Generation Li-Ion Batteries

Chalcopyrite ZnSiP2 has emerged as a promising anode material for next generation Li-ion-based batteries due to its high theoretical capacity. First principles multiple-dopant effect computations were made on the structural, electronic, magnetic, and thermodynamic responses for chalcopyrite ZnSiP2(1−x)Sbx, ZnSiP2(1−x)Bix, Zn(1−x)BaxSiP2, and Zn1−xBaxSiP2(1−x)Sbx, using both the norm conserving, ultra-soft pseudopotentials with generalized gradient approximation (GGA+PBE) and the main frame of density functional theory. Lattice coefficient volume, bulk modulus, formation energy, and total energy of host materials were computed and compared with experimental and theoretical results. Energy band gap for the pure chalcopyrite ZnSiP2 system (1.4 eV) matches previous data and validates the accuracy of current calculations as doping concentration (x = 0.6, 0.9, and 0.12) of (Sb, Bi, and Ba) at Zn and P sites increases. The corresponding band gap decreases, resulting in greater enhancement in electronic conductivity. Finally, the phonon dispersion relation, phonon density of states, vibration frequencies of phonon, Gibbs free energy, enthalpy, entropy effect, and Debye temperature (θ D) were estimated to confirm the thermodynamic stability of both pure and doped systems. These investigations are predicted to contribute a deeper sympathy of the doping effects on ZnSiP2, facilitating further advancements in anode materials design for Li-ion batteries.

Lithiophilic Multichannel Layer to Simultaneously Control the Li-Ion Flux and Li Nucleation for Stable Lithium Metal Batteries.

Although the Li metal has been gaining attention as a promising anode material for the next-generation high-energy-density rechargeable batteries owing to its high theoretical specific capacity (3860 mAh g-1), its practical use remains challenging owing to inherent issues related to Li nucleation and growth. This paper reports the fabrication of a lithiophilic multichannel layer (LML) that enables the simultaneous control of Li nucleation and growth in Li-metal batteries. The LML, composed of lithiophilic ceramic composite nanoparticles (Ag-plated Al2O3 particles), is fabricated using the electroless plating method. This LML provides numerous channels for a uniform Li-ion diffusion on a nonwoven separator. Furthermore, the lithiophilic Ag on the Li metal anode surface facing the LML induces a low overpotential during Li nucleation, resulting in a dense Li deposition. The LML enables the LiNi0.8Co0.1Mn0.1O2|| Li cells to maintain a capacity higher than 75% after 100 cycles, even at high charge/discharge rates of 5.0 C at a cutoff voltage of 4.4 V, and achieve an ultrahigh energy density of 1164 Wh kg-1. These results demonstrate that the LML is a promising solution enabling the application of Li metal as an anode material in the next-generation Li-ion batteries.

Densification of Alloying Anodes for High Energy Lithium-Ion Batteries: Critical Perspective on Inter- Versus Intra-Particle Porosity.

High Li-storage-capacity particles such as alloying-based anodes (Si, Sn, Ge, etc.) are core components for next-generation Li-ion batteries (LIBs) but are crippled by their intrinsic volume expansion issues. While pore pre-plantation represents a mainstream solution, seldom do this strategy fully satisfy the requirements in practical LIBs. One prominent issue is that porous particles reduce electrode density and negate volumetric performance (WhL-1) despite aggressive electrode densification strategies. Moreover, the additional liquid electrolyte dosage resulting from porosity increase is rarely noticed, which has a significant negative impact on cell gravimetric energy density (Whkg-1). Here, the concept of judicious porosity control is introduced to recalibrate existing particle design principles in order to concurrently boost gravimetric and volumetric performance, while also maintaining the battery's cycle life. The critical is emphasized but often neglected role that intraparticle pores play in dictating battery performance, and also highlight the superiority of closed pores over the open pores that are more commonly referred to in the literature. While the analysis and case studies focus on silicon-carbon composites, the overall conclusions apply to the broad class of alloying anode chemistries.

Structural modeling of high-entropy oxides battery anodes using x-ray absorption spectroscopy

High-entropy oxides (HEOs) are single phase solid solutions where five or more metals share the same sublattice, giving rise to unexpected features in various fields of applications. Recently, HEOs have emerged as an alternative conversion electrode anode material for next-generation Li-ion batteries, where the combination of several different elements in a single solid solution can synergistically act to overcome some of its main drawbacks, improving performance. Due to their chemical complexity, x-ray absorption spectroscopy (XAS) emerges as an appropriate technique to study the electronic (x-ray absorption near edge structure, XANES) and local structure (extended x-ray absorption fine structure, EXAFS) of these compounds as a function of cycling. This work aims to highlight the capabilities of XAS as an element-specific probe to understand a material’s structure at the atomistic level through EXAFS modeling of (MgFeCoNiCuZn)O high-entropy system and how to extract valuable information about the bond distance, number of near neighbors, and local disorder, which are crucial to a full understanding of the electrochemical reaction mechanisms of such battery electrodes.

Enabling high capacity and reversible Li storage in indium(III) oxide anode surrounded by carbon nanotube matrix

In2O3 is one of the post-transition metal oxides that can be a potential anode material for the Li-ion batteries (LIBs) because of its high theoretical capacity (869 mAh g−1) and low operating voltage (0.8 V vs Li/Li+) compared to other metal oxides. However, they have rarely been used in practical applications because of typical challenges such as irreversible capacity, unstable cycling stability, and poor coulombic efficiency. In this study, carbon nanotubes (CNTs) were successfully combined with In2O3 nanoparticles (NPs) via a solvothermal process. The In2O3 NPs and CNTs were homogeneously mixed by controlling the CNT dispersion (functionalization and appropriate solvent) and mixing sequence (dissolving the In2O3 precursor in the CNT-dispersed solution followed by thermal annealing). In addition, an increase in the oxygen vacancies in the In2O3 NPs by controlling the thermal annealing conditions (In2O3/CNT_Ar) could enhance robust binding with CNTs, increase the number of Li-ion binding sites, and improve the electrical conductivity. Therefore, at an appropriate ratio of In2O3 and CNT (92:8, w/w), the In2O3/CNT_Ar demonstrated remarkable cycling performance (830 mAh g−1 at a current density of 200 mA g−1 after 100 cycles) and rate capability (65% retention at 5 A g−1 relative to 100 mA g−1), which outperformed most In2O3-based anodes previously studied. Therefore, In2O3/CNT_Ar is a promising anode material for use in next-generation LIBs.

Operando Building of a Superior Interface Hybrid Film Enables Chemomechanically Durable Co-Free Ni-Rich Cathodes.

The Co-free Ni-rich layered cathodes become pivotal to reduce cost and increase benefit toward next-generation Li-ion batteries yet raise a major challenge for their extremely fragile cathode-electrolyte interface (CEI) film. Herein, we report the in situ construction of the Si/B-enriched organic-inorganic hybrid CEI films on LiNi0.9Mn0.1O2 (NM91) with the assistance of tris(trimethylsilyl) borate (TMSB) additive. The hybrid film exhibits superior Young's modulus, mechanical strength, and ductility, which greatly dissipate the microstrain of Co-free Ni-rich cathodes under various states of charge with high structural integrity. Furthermore, the surface oxygen anions have been significantly stabilized by bonding with the Si and B ions of TMSB with high safety. These merits enable a durable Co-free Ni-rich layered cathode with 96.9% and 87.7% capacity retentions (versus 72.7% and 70.2% of NM91) at a high rate of 5C and a high-temperature of 55 °C after 100 cycles. In a pouch-type full cell, 88.8% of initial capacity is still maintained after cycling at 1C for 500 times, greatly expediting the development and application of Co-free Ni-rich layered cathodes.

Bi-Directional H-Bonding Modulated Soft/Hard Polyethylene Glycol-Polyaniline Coated Si-Anode for High-Performance Li-Ion Batteries.

Ultrahigh-capacity silicon (Si) anodes are essential for the escalating energy demands driven by the booming e-transportation and energy storage field. However, their practical applications are strictly hampered by their intrinsically low electroconductivity, sluggish Li-ion diffusion, and undesirably large volume change. Herein, a high-performance Si anode, comprised of a modulated soft/hard coating of polyethylene glycol (PEG) (as Li-ion conductor) and polyaniline (PANI) (as electron conductor) on the surface of Si nanoparticles (NPs) through H-bonding network, is introduced. In this design, the abundant ─OH groups of soft PEG allow it to uniformly cover Si NPs while the hard PANI binds to PEG through its ─N─H group, thus constructing a tight connectin between Si and PEG-PANI (PP). Consequently, the elastic PP allows Si@PP to accommodate the huge volume expansion while possessing fine electronic/ionic conductivity. Therefore, the Si@PP anode exhibits a high initial Coulombic efficiency of 90.5% and a stable capacity of 1871mAhg-1 after 100 cycles at 1Ag-1 with a retention of 85.7%. Additionally, the Si@PP anode also demonstrates a high areal capacity of 3.01mAhcm-2 after 100 cycles at 0.5Ag-1 . This work reveals a scalable interface design of multi-layer multifunctional coatings for high-performance electrode materials in next-generation Li-ion batteries.

Performance improvement of Li-rich Mn-based materials with the submicron-sized single-crystal morphology and cationic doping

Lithium-rich manganese-based cathode materials (LRMCs) can be regarded as one of the most potential cathode materials for the next-generation high-energy Li-ion batteries due to the extra oxygen redox, which can greatly increase the actual output energy density of LRMCs. Nevertheless, the structure degradation and inevitable loss of oxygen will be triggered by the irreversible oxygen redox, which will cause a significant decline in cyclic performance and limited initial Coulombic efficiency, thus restricting their industrial applicability. Herein, the LRMCs with the submicron-sized single-crystal morphology and sodium doping are prepared by molten salt treatment with NaCl. On one hand, the submicron-sized single-crystal cathode effectively reduces the diffusion path for Li+ due to the smaller particle dimensions. On the other hand, Na+ doping expands the Li slab spacing, promoting the transport of Li+. The results show that the as-prepared material can purposefully alleviate oxygen release, improve structure stability, and increase the Li+ diffusion rate for the pristine LRMCs. Moreover, the as-prepared material in this study exhibits a higher reversible capacity of 282.8 mAh g−1 at 0.1 C and displays good cyclic performance, retaining a capacity rate of 80.9% after 200 cycles at 1 C. Therefore, this study offers a potential exploration for designing LRMCs with high energy density and excellent cyclic performance, which are achieved through building submicron-sized single-crystal morphology and introducing cationic doping.

Lateral growth of Lithium dendrite enforced by 3D porous Core@Shell-Cu@Li3N protective layer toward Long-Life Lithium metal anode

Li metal is promising as the anode for next-generation Li-ion batteries; however, uncontrollable dendrite growth and severe side reactions between the Li metal and electrolyte greatly restrict its commercialization. Here, a 3D porous protective layer constructed by core@shell-Cu@Li3N particles is developed to solve the above issues. This protective layer is easily prepared just by one-step dip coating in Cu(NO3)2/N-methyl-2-pyrrolidone (NMP) solution. Due to rapid Li+ transport and good wettability of the protective layer, it effectively modulates Li+ flux and thus homogenizes Li deposition. More importantly, as confirmed by both the experimental results and phase-field simulations, the 3D porous protective layer enforces the Li dendrite to laterally grow to form an interconnected network, which causes that the subsequent Li deposition is constrained and filled in the inner space rather than savage growth. Therefore, both the symmetric battery and full cell constructed by the protected Li electrode displays much longer lifespan than the one with bare Li even in unstable liquid carbonate electrolyte. Also, this protective layer is demonstrated to be compatible with Li1+xAlxTi2−x (PO4)3 (LATP) solid-state electrolyte by suppressing the side reactions. This work paves a new and facile strategy for developing high-performance Li metal anode.

Structure and molecular interactions in 1‑ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ion pair conformers: abinitio DFT based study

Density functional theory (DFT) calculations with Grimme’s B97D functional including dispersion are employed to provide both structural and electronic insight into the multifold interactions occurring in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid [EMI][TFSI], which is currently being targeted for applications in next-generation Li-ion battery electrolytes. The geometric structure, interaction energy and natural bond orbital analysis of the ion-pair conformers of [EMI][TFSI] show differences from the conventional H-bonds. A total of six stable [EMI][TFSI] ion pair conformers were observed. Our results show that a doubly ionic H-bond exists between [EMI]+ and [TFSI]− ion pair conformers. The greater the number of multiple H-bond type interactions, the greater the absolute value of the interaction energy. Moreover, results from the NBO analysis show that, for [EMI][TFSI] ion pair conformers, charge transfer occurs mainly from the lone pairs of oxygen and nitrogen atom to the σ-type anti-bonding orbital of the C–H and π-type anti-bonding orbitals of N–C bonds. This was evident from the values of the stabilization energy E(2) associated with each electron delocalization from the donor to acceptor orbitals. There exist large numbers of multiple concomitant hydrogen bonds, but the values of the stabilization energy E(2) are generally small (E(2)n→\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ o$$\\end{document}σ* < 3 kcal/mol) for the individual H-bond interactions. The shorter the C–H···O and/or C–H···N bond is, the larger charge transfer, and the larger the stabilization energy E(2) associated with electron delocalization from donor to acceptor. Generally, the [EMI][TFSI] ion pair conformers tend to form multiple but bent H bonds, reducing the strength of the individual H bonds from a potential (linear) maximum.

Enabling High-Performance Layered Li-Rich Oxide Cathodes by Regulating the Formation of Integrated Cation-Disordered Domains.

Layered Li-rich oxide cathode materials are capable of offering high energy density due to their cumulative cationic and anionic redox mechanism during (de)lithiation process. However, the structural instability of the layered Li-rich oxide cathode materials, especially in the deeply delitiated state, results in severe capacity and voltage degradation. Considering the minimal isotropic structural evolution of disordered rock salt oxide cathode during cycling, cation-disordered nano-domains have been controllably introduced into layered Li-rich oxides by co-doping of d0-TM and alkali ions. Combining electrochemical and synchrotron-based advanced characterizations, the incorporation of the phase-compatible cation-disordered domains can not only hinder the oxygen framework collapse along the c axis of layered Li-rich cathode under high operation voltage but also promote the Mn and anionic activities as well as Li+ (de)intercalation kinetics, leading to remarkable improvement in rate capability and mitigation of capacity and voltage decay. With this unique layered/rocksalt intergrown structure, the intergrown cathode yields an ultrahigh capacity of 288.4mAhg-1 at 0.1C, and outstanding capacity retention of ≈90.0% with obviously suppressed voltage decay after 100 cycles at 0.5, 1, and 2C rate. This work provides a new direction toward advanced cathode materials for next-generation Li-ion batteries.

Enhancing reversible capacity and cycling stability of Li&lt;sub&gt;1.2&lt;/sub&gt;Ni&lt;sub&gt;0.13&lt;/sub&gt;Fe&lt;sub&gt;0.13&lt;/sub&gt;Mn&lt;sub&gt;0.54&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; by inducing low Li/Ni misalignment through Mo doping

Li-ion batteries (LIBs) are widely used in mobile devices and electric vehicles, but the traditional layered transition metal cathode material, LiTMO&lt;sub&gt;2 &lt;/sub&gt;(TM=Ni, Co, Mn, or Al), has a low energy density that cannot satisfy the demand of commercial applications. The Li-rich Mn-based layered oxides (LRLOs) are a strong competitor to the traditional layered cathode materials for their specific capacity of more than 200 mAh/g. Due to the high energy density and low cost, Li-rich Mn-based layered oxides (LRLO) have been a promising candidate cathode for next-generation Li-ion batteries. The anionic redox reaction (ARR) in LRLO destabilizes the lattice oxygen, leading to voltage degradation and capacity loss. Although iron-substituted cobalt-free Li-rich materials can achieve less voltage decay, they suffer severe cation disorder and poor kinetics. Here, we develop a simple and feasible high-valent ion doping strategy by doping Mo into Li&lt;sub&gt;1.2&lt;/sub&gt;Ni&lt;sub&gt;0.13&lt;/sub&gt;Fe&lt;sub&gt;0.13&lt;/sub&gt;Mn&lt;sub&gt;0.54&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;(LNFMO), which expands the Li layer spacing and provides a broader channel for Li&lt;sup&gt;+&lt;/sup&gt; transport, thereby improving the diffusion kinetics of Li&lt;sup&gt;+&lt;/sup&gt;, effectively suppressing the cation disorder, and further stabilizing the layered structure. As a result, the Mo-doped LRLO exhibits significantly enhanced electrochemical performance, with an initial reversible capacity of 209.48 mAh/g at 0.2 C, and the initial specific capacity increasing from 137.02 mAh/g to 165.15 mAh/g at 1 C. After 300 cycles, specific capacity remains 117.49 mAh/g for the Mo-doped cathode, and the voltage decay decreases from 2.09 mV/cycle to 1.66 mV/cycle. The Mo-doped LRLO is systematically characterized, and the mechanism of cycle stabilization is revealed, which provides an important reference for designing high performance Li-rich cathode.

Vibrationally-resolved RIXS reveals OH-group formation in oxygen redox active Li-ion battery cathodes.

Vibrationally-resolved resonant inelastic X-ray scattering (VR-RIXS) at the O K-edge is emerging as a powerful tool for identifying embedded molecules in lithium-ion battery cathodes. Here, we investigate two known oxygen redox-active cathode materials: the commercial LixNi0.90Co0.05Al0.05O2 (NCA) used in electric vehicles and the high-capacity cathode material Li1.2Ni0.13Co0.13Mn0.54O2 (LRNMC) for next-generation Li-ion batteries. We report the detection of a novel vibrational RIXS signature for Li-ion battery cathodes appearing in the O K pre-peak above 533 eV that we attribute to OH-groups. We discuss likely locations and pathways for OH-group formation and accumulation throughout the active cathode material. Initial-cycle behaviour for LRNMC shows that OH-signal strength correlates with the cathodes state of charge, though reversibility is incomplete. The OH-group RIXS signal strength in long-term cycled NCA is retained. Thus, VR-RIXS offers a path for gaining new insights to oxygen reactions in battery materials.

The sensitive aspects of modelling polymer-ceramic composite solid-state electrolytes using molecular dynamics simulations.

Solid-state composite electrolytes have arisen as one of the most promising materials classes for next-generation Li-ion battery technology. These composites mix ceramic and solid-polymer ion conductors with the aim of combining the advantages of each material. The ion-transport mechanisms within such materials, however, remain elusive. This knowledge gap can to a large part be attributed to difficulties in studying processes at the ceramic-polymer interface, which are expected to play a major role in the overall ion transport through the electrolyte. Computational efforts have the potential of providing significant insight into these processes. One of the main challenges to overcome is then to understand how a sufficiently robust model can be constructed in order to provide reliable results. To this end, a series of molecular dynamics simulations are here carried out with a variation of certain structural (surface termination and polymer length) and pair potential (van der Waals parameters and partial charges) models of the Li7La3Zr2O12 (LLZO) poly(ethylene oxide) (PEO) system, in order to test how sensitive the outcome is to each variation. The study shows that the static and dynamic properties of Li-ion are significantly affected by van der Waals parameters as well as the surface terminations, while the thickness of the interfacial region - where the structure-dynamic properties are different as compared to the bulk-like regime - is the same irrespective of the simulation setup.

Plasma-Enhanced Atomic Layer Deposition of Lithium Nickel Oxide Thin Film Model Systems

The main bottleneck in the development of the next generation of Li-ion batteries with higher energy densities, as demanded for long-range electrical mobility, is the lack of understanding and control of the reactions at the electrode-electrolyte interfaces. Reactions at the cathode side cause rapid capacity loss during cycling and represent a major issue for batteries with high-voltage cathodes, which are crucial in reaching the required energy densities. Promising candidates for use in next generation of batteries are Ni-rich Li(Ni1-x-yMnxCoy)O2 (NMC) cathodes, which show high capacity, high potential, and contribute to address the geopolitical issue of decreasing the Co content in the cathode. Ni-rich NMCs exhibit similar electrochemical properties as pure LiNiO2 and therefore LiNiO2 thin films can be used as model systems to gain fundamental understanding of the interfacial processes that hinder the large-scale implementation of Ni-rich NMCs. Atomic layer deposition (ALD) is a suitable technique to fabricate these model systems, as it gives precise control over film thickness, uniformity, chemical composition, and crystal orientation.Previous work on LiNiO2 by ALD is not extensively reported in literature. Moreover, films grown by a supercycle process, in which two ALD subcycles are alternated, suffered from a low Ni at.% and a large C content because of precursor ligand residues, and films fabricated using a complex multilayered approach showed severe Si contamination from the Li precursor [1]. In this contribution we report on ALD lithium nickel oxide (LNO) thin films with stoichiometries close to LiNiO2 and low levels of contaminants.The ALD process is based on lithium hexamethyldisilazide (LiHMDS) and nickel bis(N,N’-di-tert-butylacetamidinate) (Ni(tBu-MeAMD)2) as precursors and O2 plasma as co-reactant. 1 ALD cycle of Li2O is combined with x cycles of NiO using a supercycle approach. In this contribution we explore the relation between the Ni/Li cycle ratio x and material properties of the LNO films.The growth of the LNO films is monitored by means of in-situ spectroscopic ellipsometry. The ellipsometric data of films with a high Ni/Li cycle ratio are fitted with a general oscillator model used for NiO films, while a Cauchy model was adopted in case of a low Ni/Li cycle ratio and Li2O films. The growth per supercycle (GPSC) of LNO shows an intermixing effect, as it does not follow the linear trend calculated from the growth per cycle (GPC) values of the individual Li2O and NiO ALD processes, which are 1.0 Å/cycle and 0.34 Å/cycle respectively.XPS surface measurements show that the Ni/Li atomic ratio is tuned from 0 to 10 as function of the Ni/Li cycle ratio x. Low levels of Si and N contamination, below 4% and 2% respectively, are observed. A shift of the main peak in the Ni 2p3/2 spectrum to higher binding energies indicates a shift in oxidation state from Ni2+ to Ni3+ as decreases [2]. According to surface measurements, the LNO film with x=5 shows a stoichiometry close to LiNiO2, but depth profile measurements indicate that the Ni at.% is significantly higher in the bulk than on the surface of the films, most certainly attributed to the formation of a Li2CO3 surface layer upon air exposure. Li2CO3 is also present in the bulk of the LNO films, but the bulk C at.% stays below 4%.These results show that we can use ALD to fabricate a high-voltage cathode model system, which we plan to characterize in-situ and post-mortem in combination with both liquid and solid electrolytes to study the cathode-electrolyte interface.[1] Maximov et al., Energies, 13 (2020) 2345[2] Fu et al., Applied Surface Science 441 (2018) 1048 This work is part of the ‘BatteryNL – Next Generation Batteries based on Understanding Materials Interfaces’ project (with project number NWA.1389.20.089) of the NWA research programme ‘Research on Routes by Consortia (ORC)’ funded by the Dutch Research Council (NWO). Figure:(a) The GPSC of LNO ALD process shows an intermixing effect when comparing the experimental results with the expected GPSC based on the two processes (b) Ni 2p3/2 XPS spectrum for different Ni/Li cycle ratios x. A shift to higher binding energies is observed with decreasing x, indicating a shift from Ni2+ to Ni3+. (c) XPS surface measurements of LNO films show low levels of contaminants and a Ni/Li atomic ratio varying with the Ni/Li cycle ratio. (d) Depth profile of LNO with x=5 shows an increased Ni at.% and a low C at.% in the bulk of the film. Figure 1

Stabilized Positive Electrode Material to Enable High Energy/Power Density Lithium-Ion Batteries

Recently, the large-scale deployment of electric vehicles (EVs) and stationary battery systems has putforward urgent requests for rechargeable batteries with higher energy/power density and longerlifespans. As such, next-generation Li-ion batteries (LiBs) are expected to meet these requirements. Thepossibility of using Ni-rich high-capacity cathode materials (NMC) can help to achieve that goal, however,they still suffer from significant capacity fade via several chemical and mechanical degradation modes.One is crack formation within secondary particles which leads to parasitic reactions that evolve oxygenand potentially initiate the formation of inactive crystal structures. LiBs mechanical and chemicaldegradation mechanisms can be extended by applying protective coatings to the cathode’s surface. Manystudies explore atomic layer deposition (ALD) for this purpose. However, the complementary molecularlayer deposition (MLD) technique might offer the benefit of depositing flexible hybrid coatings that canaccommodate potential volume changes of the electrode during the battery cycling. This study reportsthe deposition of novel organic-inorganic films via the ALD-MLD method. Characterization analysis suchas FTIR, XPS, SEM-EDS, and TEM confirmed the film deposition on the surface of the NMC electrode.Besides, the electrochemical results showed the enhancement of the coated electrode, as evidenced byproviding a longer life with a 93% capacity retention after 150 cycles (3.0-4.4 V vs. Li/Li+), while theuncoated one retained only 83% of its initial capacity. Moreover, in situ dilatometry showed irreversiblevolume change for uncoated NMC while it was mostly reversible for coated ones during the cycling. Itrevealed the dilation behavior of the electrode, resulting in crack formation, which is significantlysuppressed for the coated samples. Stable cycling of Ni-rich cathode materials in crucial conditions suchas high voltage windows and elevated temperatures is still extremely challenging. To evaluate this, in situdilatometry was performed at elevated temperatures (40 °C and 55 °C) and higher voltage ranges (3.0-4.6V). The results confirmed that in both conditions, the dilation behavior of the coated sample is still undercontrol while the capacity is comparable to the uncoated sample. This revealed that the coatings presentgood lithium-ion kinetics and reduce electrolyte decomposition. Overall, this work showed the liability ofthe ALD-MLD films deposited on NMC electrodes to mitigate the degradation mechanisms and providesinsight into a method that seems promising as a protective and elastic coating for future high-energylithium-ion battery cathodes. Figure 1

The potentials of LiMnPO4 cathode material for aqueous Li-ion batteries: An investigation into solid state and green chemistry approaches

The phospho-olivine LiMnPO4 nanocrystal holds promise as a cathode material for next-generation Li-ion batteries (LIBs). In this study, we employed solid-state and green chemistry approaches to prepare LiMnPO4 powders, with aloe vera extract serving as a capping agent for the latter approach. Selective synthesis of nanoparticles with more active sites for efficient Li+ intercalation-deintercalation was achieved. The phase purity, morphology, and composition of the nanoparticles were characterized using XRD, SEM/TEM, and EDS, respectively. Electrochemical performance was evaluated through cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS) in an aqueous environment. The solid-state synthesized LiMnPO4 nanoparticles (LiMnPO4-SS) exhibited electrolyte-dependent performance but demonstrated good reversibility of Li+ extraction and insertion. Specific capacity, retention of discharge capacity, and Coulombic efficiency were found to be 92.3 ± 0.5 mAhg−1, 98 %, and 93 %, respectively, after 50 cycles at 0.2 C. Additionally, energy density was measured as 15.8 ± 1.4 Whkg−1 at 189.2 ± 1.9 Wkg−1 power density. The green-synthesized LiMnPO4 nanoparticles (LiMnPO4-GS) showed a specific capacity of 106.4 ± 0.9 mAhg−1 (corresponding to ∼62 % of theoretical capacity) after 50 cycles, with capacity retention of ∼97 % and ∼80 % Coulombic efficiency. The energy density was 18.2 ± 1.7 Whkg−1 at 218.1 ± 2.1 Wkg−1 power density. EIS measurements indicated reduced charge transfer resistance for LiMnPO4-GS, optimizing interfacial electrochemical reaction activity. The observed regular micromorphology and (200) plane of nanosized LiMnPO4 contributed to the excellent electrochemical performance. Overall, this investigation highlights the correlation among synthesis method, calcination temperature, electrolyte, crystal structure, and morphology, providing insights for the design of next-generation LIBs.

Constructing a stable interface on Ni-rich LiNi0.8Co0.1Mn0.1O2 cathode via lactic acid-assisted engineering strategy

Ni-rich layered oxides are potential cathode materials for next-generation high energy density Li-ion batteries due to their high capacity and low cost. However, the inherently unstable surface properties, including high levels of residual Li compounds, dissolution of transition metal cations, and parasitic side reactions, have not been effectively addressed, leading to significant degradation in their electrochemical performance. In this study, we propose a simple and effective lactic acid-assisted interface engineering strategy to regulate the surface chemistry and properties of Ni-rich LiNi0.8Co0.1Mn0.1O2 cathode. This novel surface treatment method successfully eliminates surface residual Li compounds, inhibits structural collapse, and mitigates cathode-electrolyte interface film growth. As a result, the lactic acid-treated LiNi0.8Co0.1Mn0.1O2 achieved a remarkable capacity retention of 91.7% after 100 cycles at 0.5 C (25 °C) and outstanding rate capability of 149.5 mA h g−1 at 10 C, significantly outperforming the pristine material. Furthermore, a pouch-type full cell incorporating the modified LiNi0.8Co0.1Mn0.1O2 cathode demonstrates impressive long-term cycle life, retaining 81.5% of its capacity after 500 cycles at 1 C. More importantly, the thermal stability of the modified cathode is also dramatically improved. This study offers a valuable surface modification strategy for enhancing the overall performance of Ni-rich cathode materials.

A Brief Overview of Silicon Nanoparticles as Anode Material: A Transition from Lithium-Ion to Sodium-Ion Batteries.

The successful utilization of silicon nanoparticles (Si-NPs) to enhance the performance of Li-ion batteries (LIBs) has demonstrated their potential as high-capacity anode materials for next-generation LIBs. Additionally, the availability and relatively low cost of sodium resources have a significant influence on developing Na-ion batteries (SIBs). Despite the unique properties of Si-NPs as SIBs anode material, limited study has been conducted on their application in these batteries. However, the knowledge gained from using Si-NPs in LIBs can be applied to develop Si-based anodes in SIBs by employing similar strategies to overcome their drawbacks. In this review, a brief history of Si-NPs' usage in LIBs is provided and discuss the strategies employed to overcome the challenges, aiming to inspire and offer valuable insights to guide future research endeavors.

Revealing the key role of MnSiO3 in boosting the lithium storage performance of bamboo-derived anode materials

Carbon/manganese oxide hybrid materials, as potential candidates for lithium-ion battery anode materials, have attracted extensive attention due to their abundant resources and simple preparation. However, poor rate performance, weak cycle stability, and relatively high cost still limit their further development as commercial materials for next-generation Li-ion batteries. Herein, a novel carbon/manganese oxide hybrid material was fabricated from low-cost carbonized bamboo leaves and manganese nitrate for the lithium-ion battery anode. Interestingly, an additional MnSiO3 component found in this hybrid material is able to increase the material's intrinsic conductivity for improving the charge transfer as well as to enhance the Li+ diffusion ability for accelerating the reaction kinetics. Thus, the rate capability and cycle performance of the prepared hybrid material with additional MnSiO3 have been significantly improved by 18.4 and 52.6 %, respectively, compared to hybrid material without the MnSiO3 component. Moreover, the cycle performance of this hybrid material is also superior to that of many similar carbon/silicate and carbon/manganese oxide hybrid materials. Thanks to the excellent electrochemical performance, our hybrid material has also been successfully fabricated into a lithium-ion full battery, which displays considerable energy storage performance and good practical application ability.