Specific Discharge Capacity Research Articles

Copper-doping enhanced electrochemical performance of cobalt embedded nitrogen-doped porous carbon dodecahedra in lithium-ion half/full batteries

The creation of negative electrode materials that have quick redox kinetics, reduced volumetric expansion, and a high reversible specific capacity is the linchpin to the advancement of lithium-ion batteries. Here, we prepared copper-doping cobalt-embedded nitrogen-doped porous carbon (CoCu@NC) by calcining copper-modified ZIF-67. The unique hollow structure presents a fast ionic diffusion channel and good structural stability. Density functional theory (DFT) calculation testifies that Cu-doping can regulate the electronic structure of the CoCu@NC surface as well as enhance lithium ions adsorption capacity on nitrogen sites. Furthermore, the presence of N and Cu could generate more defects, thereby achieving rapid storage reaction kinetics of lithium ions. Benefiting from the cooperative effect between Co and Cu double-doped at NC, strain and stress are alleviated during lithium-ion intercalation/deintercalation processes, thus improving cycling stability and performance. Therefore, CoCu@NC shows a superior capacity of 1155.10 mAh g−1 at a current density of 0.5 A g−1, and good stability with 310.90 mAh g−1 at 10 A g−1 after 600 cycles. The assembled LiCoO2//CoCu@NC-7 lithium-ion full battery can achieve a discharge-specific capacity at 3 A g−1 for 182.60 mAh g−1 after 500 cycles.

Synthesis of porous Mg2MnO4 spinel microspheres and enhanced lithium storage properties

Porous Mg2MnO4 spinel microspheres were synthesized by a facile solvothermal method. Various techniques such as X-ray powder diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, were used to characterize the phase composition, morphology and electronic structure of materials. The results show that Mg2MnO4 spinel material was obtained at the temperature of 600–800 °C and has a microsphere structure. The microspheres were assembled by nanoparticles, and the particle size increases with the increase of annealing temperature. Analyses of XPS spectra reveal that Mn exists in multiple valence states (+2, +3, +4) in Mg2MnO4 materials, and all the materials are mixed spinel with Mg2+ and Mn2+/3+/4+ ions occupy both tetrahedral and octahedral sites of spinel structure, and the degree of inversion decreases with increasing annealing temperature. Mg2MnO4 microspheres exhibit excellent lithium storage performance, the first discharge specific capacity of M2MO-8 is 835.3 mAh g−1 under a voltage window of 0–3 V and with a current density of 100 mA g−1, and after 100 cycles the discharge capacity of the material is as high as 406.5 mAh g−1. In addition, this material shows high cyclic reversibility. The enhanced lithium storage properties of the material can be attributed to its porous structure, which promote the transport of lithium ions and reduce the damage to the structure caused by the volume change during the charge and discharge process.

Effective improvement of lithium-ion battery anode performance of Ti3C2 by alkali metal ion treatment strategy

MXene has emerged as a promising electrochemical energy storage material due to modifiable layered structure and good electrical conductivity. However, its lamellar stacking has severely limited the electrochemical performance during charging and discharging. Herein, the Li-treated Ti3C2 and Na-treated Ti3C2 nanocomposites are prepared by hydrothermal treatment. Li-treated Ti3C2 exhibits the largest discharge specific capacity, with an initial capacity of 551.5 mA h/g at a rate of 0.1 A/g, which is 81.3 mA h/g higher than Na-treated Ti3C2. After 200 cycles, the Li-Ti3C2 possesses a final capacity of 321.1 mA h/g, better than Na-Ti3C2 (151.7 mA h/g) and Ti3C2 (119.3 mA h/g). The Li-Ti3C2 shows superior cycling performance at a high rate of 2 A/g and a capacity retention rate of 84 % after 1000 cycles. During hydrothermal treatment, the in situ generated TiO2 plays a crucial role in the targeted introduction of metal ions. Density functional theory (DFT) calculations verify that LiTiO2 phase in Li-treated Ti3C2 possesses low band gap and lowest Li migration barrier. The synergy of these factors leads to the improved electrochemical performance of Li-treated Ti3C2. This work provides novel design strategies for developing MXene materials as high performance lithium-ion batteries.

The high-rate cycling stability of the LiFe0.6Mn0.4PO4/C cathode material is enhanced through in-situ Nb-doping

LiFe0.6Mn0.4PO4/C, due to its low cost and safety advantages, is gradually becoming a safe and reliable commercial lithium battery storage material. However, its lower capacity at high rates and poor cycle performance limit its further industrial application. To address this, this work used a one-step solvothermal method to prepare Li(Fe0.6Mn0.4)1‑xNbxPO4 (x = 0, 0.01, 0.02, 0.03) cathode materials to improve electrochemical performance. Characterization of the samples indicates that Nb doping promoted the growth of the material's [001] crystal orientation, thus enhancing the lithium ion diffusion rate, effectively reducing electrode polarization and charge transfer resistance, which helps to explain its excellent rate performance. More importantly, Nb doping increases the M-O bond energy, making the LMFP/C metal-oxygen framework more stable, and enhancing the stability of the crystal structure of lithium ions intercalating and deintercalating during cycling. The electrochemical test results further indicate that the LFMP/CNb0.02 cathode exhibits excellent electrochemical performance. It has remarkable capacities of 156.9 mAh·g‑1 at 0.2 C and 135.9 mAh·g‑1 at 1 C, particularly showing an initial discharge specific capacity of 121.4 mAh·g‑1 at a high rate of 5 C. After 500 cycles, it still maintains a capacity of 114.3 mAh·g‑1, with a capacity retention rate of 94.15 %, significantly outperforming the original LMFP/C (initial discharge specific capacity of 109.8 mAh·g‑1) which only retains 61.47 % of its capacity after 300 cycles.

Surface modification of LiFePO4 cathode enabled by highly Li+ mobility wrapping layer towards high energy and power density

Surface-modified cathode materials have been developed to achieve high-performance lithium secondary batteries with higher capacity, rate capability, and longer cycle performance than bulk active materials. In this study, a new surface-modified active material was explored through a low-temperature in situ-solution wrapping method (LiFePO4@Li4SiO4 composite). In addition, high Li-ion and electronic conductivity materials with amorphous nanostructures, in which the bulk LiFePO4 nanoparticles were covered with a Li4SiO4 layer, were demonstrated. In lithium-ion batteries, the LiFePO4@Li4SiO4 composite demonstrated enhanced charge transfer kinetics, which lowered the interfacial resistance between electrode and electrolyte and resulted in enhanced electrochemical performance when compared to that of bulk LiFePO4. Furthermore, Li4SiO4 is introduced as a surface stabilizer and effective Li-ion conductor to avoid side reactions and prevent the dissolution of active materials into the electrolyte. The designed cathode delivers a high specific discharge capacity of 171.8 mAh g-1 at 0.1 C with 99.76 % capacity retention after 150 cycles and a high capacity of 121.2 mAh g-1 at 10 C. Moreover, Li-ion full batteries employing LiFePO4@Li4SiO4 and graphite displayed a high specific energy density of 416.078 Wh kg-1 at a power density of 69.34 W kg-1 at 5 C. In summary, this paper reports a new strategy based on low-temperature in situ solution phase wrapping materials for developing active materials for high energy-power density energy storage devices.

A novel hybrid sodium ion capacitor based on Na [Ni0.60Mn0.35Co0.05] O2 battery type cathode and presodiated D-Ti3C2Tx pseudocapacitive anode

The combination of the high-power density of supercapacitors and the high energy density of batteries makes hybrid sodium-ion capacitors (HSICs) a promising device. HSICs can provide better performance characteristics by harnessing both ion adsorption/desorption in the capacitor-type electrode and sodium-ion intercalation in the battery-type electrode. Here, the synthesis of MXene (Ti3C2Tx), a two-dimensional (2D) carbide and nitride is reported. Delaminated MXene (D-Ti3C2Tx) is a promising candidate for anode material in HSIC due to its large surface area (∼ 42 m2/g) and good electronic conductivity. Electrochemical study indicates that D-Ti3C2Tx anode exhibits a high discharge capacity of ∼213 mAh/g at a current rate of 20 mA/g. Further the presodiated D-Ti3C2Tx anode is paired with Na [Ni0.60Mn0.35Co0.05] O2 (P2-NMC) cathode to obtain the configuration of HSIC. The HSIC exhibits good specific capacitance of ∼187 F/g and specific discharge capacity of ∼110 mAh/g at a current density of 10 mA/g, according to the electrochemical analysis. A notable improvement in specific energy density (∼ 256 Wh/kg) and specific power density (∼579 W/kg) is also demonstrated by the HSIC. With P2-NMC being used as the cathode material rather than traditional activated carbon, there has been a rise in specific energy density.

Silicon/graphite/amorphous carbon composites as anode materials for lithium-ion battery with enhanced electrochemical performances

Silicon has emerged as one of the most promising anode materials for next-generation lithium-ion batteries due to its exceptional specific capacity and abundant resources. However, its widespread application is hindered by structural deformability and low intrinsic conductivity. By strategically integrating a conductive carbon matrix with silicon, it becomes feasible and efficient to enhance the electrical conductivity of silicon and accommodate the stress-induced volume expansion during battery operation. In this study, a series of silicon/graphite/amorphous carbon (Si/G/C) composites were prepared using mechanical milling and carbothermal reduction. The study focused on two main aspects: the effect of the ratio of micro-sized silicon to flake graphite on the properties of the composite and the compatibility of different-scale silicon particles (micro-sized silicon and nano-sized silicon) and different kinds of natural graphite (flake graphite and cryptocrystalline graphite). The results reveal that when micro-sized silicon and flake graphite are combined, the graphite is fragmented more thoroughly, resulting in smoother surfaces and reduced aggregation of secondary particles. The composites with a mass ratio of 7:3 micro-sized silicon to flake graphite have the smallest specific surface area and pore size, homogeneous distribution, and stable structure. This exceptional carbon-to-silicon ratio endows the Si/G/C composite with rapid reaction kinetics, enabling a specific discharge capacity of 854.1 mAh g-1 after 200 cycles at 1A g-1. The findings offer valuable insights into the design and optimization of silicon-based anode materials for next-generation lithium-ion batteries.

Design of Na2Ti3O7/Na2Ti6O13 nanorods for sodium-ion batteries from titanium oxysulfate solution

Sodium titanate is currently a widely studied anode electrode material for sodium-ion batteries, showing promising potential for large-scale production and applications. Current research focuses on Na2Ti3O7, Na2Ti6O13, and their mixed compositions Na2Ti3O7/Na2Ti6O13, utilizing high-purity titanium compounds as raw materials. In this study, precursors of biased titanate with three different sulfur contents (3.20 %, 2.04 %, 0.28 %) are prepared using a self-seeding hydrolysis method and a titanium oxysulfate (TiOSO4) solution as the starting material. During the synthesis of sodium titanate, sodium consumption occurs due to sulfur, resulting in a mixed phase comprising Na2Ti3O7/Na2Ti6O13. However, when the sulfur content is very low, a single phase of Na2Ti3O7 can be obtained. Notably, Na2Ti3O7/Na2Ti6O13 synthesized from biased titanate with high sulfur content exhibits a larger percent of Na2Ti6O13, which improves rate capability and cycling stability. The initial discharge specific capacity at 177 mA·g−1 is 57.4 mAh·g−1, and after 1000 cycles, the discharge capacity reaches 22.7 mAh·g−1. Designing mixed materials Na2Ti3O7/Na2Ti6O13 from TiOSO4 solution represents one of the pathways to achieve high-performance sodium titanate materials.

Efficient synthesis of LiV2O5 as the cathode materials for high specific energy thermal batteries

LiV2O5 is considered an ideal cathode material for high specific energy thermal batteries due to its high voltage and high thermal stability. However, pure LiV2O5 is difficult to synthesize due to the multivalent nature of vanadium. In this paper, LiV2O5 powders in bulk were synthesized by using commercial V2O5 and LiBr as raw materials, followed by a simple ball milling and a sintering at 600 ℃ for 20 min. The discharge specific capacity of LiV2O5 cathode can reach 360.67 mAh g−1 at 0.05 A cm−2. Furthermore, LiV2O5/CFx cathode shows a specific capacity with 795 mAh g-1 at a cut-off voltage of 1.5 V, demonstrating significant potential for practical applications and providing a new approach for using CFx as a cathode material for thermal batteries. This article not only provides a method for mass-producing pure LiV2O5 cathode materials, but also explores a feasible strategy for using CFx with high-voltage and high specific capacity as cathode materials for thermal batteries.

Mitigating Dissolution to Enhance the Performance of Pillar[5]quinone in Sodium Batteries

AbstractSodium‐ion batteries using organic electrode materials are a promising alternative to state‐of‐the‐art lithium‐ion batteries. However, their practical viability is hindered by challenges such as a low specific capacity of the organic electrode materials, or their dissolution in the electrolyte. We herein present a double mitigation strategy to enhance the performance of pillar[5]quinone (P5Q) as positive electrode material in sodium batteries. Using 5 m sodium bis(fluorosulfonyl)imide in succinonitrile as highly concentrated electrolyte, as well as encapsulating P5Q in CMK‐3 (Carbon Mesostructured by KAIST with hexagonally ordered rod‐like carbon domains) as templated ordered mesoporous carbon, we achieve a record cycling performance with improved cycling stability even at elevated temperature (40 °C). The P5Q@CMK‐3 composite electrode delivers 430 mAh g−1 specific discharge capacity at 0.2 C rate with 90 % retention over 200 cycles. This corresponds to an energy density of 831 Wh kg−1 (based on P5Q mass) and surpasses previous reports on pillarquinones. When operated at 40 °C, the P5Q@CMK‐3 composite electrodes deliver a specific discharge capacity of 438 mAh g−1 with 88 % capacity retention over 500 cycles (0.02 % per cycle). This study underscores the crucial role the electrolyte plays in advancing organic sodium batteries, offering a promising avenue for the future of sustainable energy technologies.

Accelerating Lithium‐Ion Transfer and Sulfur Conversion via Electrolyte Engineering for Ultra‐Stable All‐Solid‐State Lithium–Sulfur Batteries

AbstractOffering ultrahigh energy density and exceptional safety, all‐solid‐state lithium–sulfur batteries (ASSLSBs) can be one of the most promising energy storage systems if their inherent challenges, including slow Li+ mass transport and insufficient sulfur utilization efficiency, are completely tackled. In this work, an amide‐based electrolyte additive with a high Gutmann donor number is used to construct a deep eutectic system, a “one‐stone‐two‐birds” solution to address these issues. In particular, an acetamide is used to interact with the insulative Li2S via a strong S─H bond and Li─O bond to boost the electrochemical reaction kinetics of lithium‐sulfur (Li─S) chemistry and sulfur utilization and simultaneously form a deep eutectic LiTFSI‐acetamide system to enhance ionic conductivity of solid polymer electrolytes (SPEs). Such a seamless integration of this system into the solid‐state LSBs helps deliver a high initial discharge specific capacity of 1012 mAh g−1 at 0.05 C and attain a stable cyclability for 1300 cycles at 0.1 C. This remarkable achievement in high performance and stability can effectively facilitate the commercialization of ASSLSBs.

Extraordinary Corrosion Inhibition of Potassium Stannate and Riboflavin Hybrid Additive on the Al Alloy Anode of Alkaline Al‐Air Batteries

AbstractAl‐air batteries (AABs) are regarded as a promising future alternative energy source due to their supposedly high energy density. The corrosion of AABs resulting from the hydrogen evolution corrosion and self‐corrosion occurring during their use in alkaline solutions represented a significant obstacle to their development, considerably limiting their commercialization. In this study, we examined the corrosion inhibition efficiency of the hybrid anticorrosive agent composed of potassium stannate (K2SO3) and riboflavin (Rib) when used as an addition in the electrolyte of an alkaline AAB. The experimental results demonstrated that the incorporation of the hybrid corrosion inhibitor leads to an anticorrosion inhibition efficiency of 70.2%, an increase in the discharge specific capacity, and specific energy of the entire battery from 913 mAh g−1 and 1023 Wh kg−1 to 2128 mAh g−1 and 2511 Wh kg−1, respectively. The adsorption behavior of the additives on the surface of the Al alloy was studied using surface characterization techniques such as scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS), atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy (XPS). It revealed that the incorporation of the hybrid additive leads to the formation of a dense and uniform protective layer on the surface of the Al anode during the discharge process. This film effectively prevents direct contact between the alkaline electrolyte and the Al surface, drastically reducing the formation of possible hydrogen interactions between the electrolyte and the anode. Consequently, the hydrogen evolution reaction (HER) is efficiently inhibited, and the overall performance of the AAB is improved. Thus, this electrolyte regulation strategy presents a novel approach to studying high‐efficiency alkaline AABs.

The research of electrochemical performance of Mg-doped NaNi1/3Mn1/3Fe1/3O2 positive electrode materials

Abstract The demand for Li-ion batteries is increasing year by year, which poses a great challenge to the scarce Li and Co resources. Na-ion batteries are considered to be one of the potential energy storage batteries because of their low raw material cost, wide source of sodium resources, and prices that are not susceptible to market fluctuations. The layered oxide positive electrode (such as NaNi1/3Mn1/3Fe1/3O2, NMF) is a potential replacement due to its high-capacity characteristics and low-cost advantages. However, the rate performance of NMF is compromised by the slow migration kinetics of Na+ ions. Here, we used the Mg doping strategy to realize the enhancement of the rates and cycling properties of NMF. Our research shows that the 2% Mg-doped cathode material has superior rate performance and cycling performance. The discharge-specific capacities are 120.5 mAh/g at 0.1C and 88.9 mAh/g for 100 cycles at 0.5C with a high retention rate (85.2%).

Functional ternary salt construction enabling an in-situ Li3N/LiF-enriched interface for ultra-stable all-solid-state lithium metal batteries

Poly(ethylene oxide)-based polymer all-solid-state lithium metal batteries (ASSLBs) have received widespread attention due to their low cost, good process ability, and high energy density. Nevertheless, the growth of Li dendrites within polymer solid-state electrolytes damages the reversibility of Li anodes and still impedes their widespread application. One efficient strategy is to construct a superior solid electrolyte interface. Herein, a stable interface enriched with Li3N and LiF is in-situ formed between Li anode and a ternary salt electrolyte. This ternary salt electrolyte is innovatively designed by introducing lithium bis(trifluoromethane sulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl)imide (LiFSI), and LiNO3 to poly(ethylene oxide) matrix. Surface characterization indicates that LiNO3 and LiFSI contribute to forming a Li3N-LiF-enriched interface and meanwhile LiTFSI ensures excellent conductivity. Theoretically, among various Li compound components, Li3N has high ionic conductivity, which is beneficial for reducing overpotential, while LiF has high interfacial energy which can enhance nucleation energy and suppress the formation of Li dendrites. The experimental results show that ASSLBs coupled with LiFePO4 cathode display extremely excellent cycle stability approximately 2200 cycles at 2 C, with a final and corresponding discharge specific capacity of 96.7 mA h g−1. Additionally, a schematic illustration of the working mechanism for the Li3N-LiF interface is proposed.

Regulating H-bonded network of aqueous electrolytes for stable and energy-dense Al-air batteries

Aluminum-air batteries offer unique advantages over other aqueous batteries in terms of environmental friendliness, energy density, resource abundance, and cost-effectiveness. Nevertheless, the parasitic hydrogen evolution reaction (HER) of anode presents severe challenges for stable and long-term operation of batteries. Here we found that the mixed solution with strong H-bond network has a significant inhibitory effect on the self-discharge and HER of Al anode in alkaline electrolyte. And establishing the relationship between the molecular structure of the cosolvent (carbon chain lengths and hydrogen bond acceptors) and the strength of the hydrogen bonding network of the electrolyte. The as-constructed Al-air battery with ethylene glycol (EG) cosolvent demonstrates a remarkable increased discharge specific capacity of 2725 mAh g-1, corresponding to the Al anode utilization of 91.4%. The operation time also extends to 160 hours at 5 mA cm-2. This work provides new avenues to understand the role of H2O in aqueous electrolytes and explore low-cost and effective approaches for the development of next-generation aqueous Al-air batteries.

An anthraquinone derivative for modulating the energy levels of polysulfide molecular orbitals to enhance the kinetics of redox reactions

The shuttle effect of lithium polysulfides (LiPSs) and the slow kinetics of sulfur redox reactions severely hinder the commercialization of lithium-sulfur (Li–S) batteries. In this study, 2,6-dihydroxyanthraquinone (DHAQ) is absorbed onto the surface of carbon materials through π-π interactions to facilitate the adsorption and catalytic conversion of LiPSs. Electrostatic potential (ESP) results indicate that introducing hydroxyl groups into the molecule enhances the carbonyl group's ability to adsorb LiPSs and thereby facilitates the formation of covalent Li-O bonds for their immobilization. The interaction between DHAQ and LiPSs results in a complex with a higher energy level for the highest occupied molecular orbital (HOMO) and a lower energy level for the lowest unoccupied molecular orbital (LUMO). This leads to enhanced redox activity, which accelerates the kinetics of LiPSs conversion reactions. Consequently, the S@DHAQ/C composite demonstrates a capacity decay rate of just 0.040 % per cycle after 600 cycles at 1 C. At a sulfur loading of 5 mg cm−2, it retains an initial discharge specific capacity of 643 mAh g−1 at 0.2 C. This work introduces a novel approach to improving polysulfide adsorption capacity through organic molecules while also accelerating the kinetics of redox reactions.

Superior electrochemical performances of Lithium vanadium oxide with coconut shell-based porous carbon as the anode of the aqueous Li ion battery

Carbon materials, as the skeleton structure of electrode materials, are composited with lithium-ion anode materials, which not only increase the electrical conductivity of the materials, but also enhance the electrochemical performance of the electrode materials. In this paper, LiV3O8@C composites were prepared by using coconut shell-based porous carbon to structurally modulate aqueous lithium-ion anode materials. And three composites with different structures and sizes were successfully synthesized by hydrothermal method, hydrothermal stirring method and improved solid-phase method. After XRD and SEM analyses, it was found that all three composites maintained the monoclinic crystal system structure of LiV3O8, and the materials prepared by the hydrothermal method showed a smooth layer structure, while the materials prepared by the hydrothermal stirring method and the solid-phase method showed nanorods with different sizes. The prepared anode materials and LiFePO4 cathode materials were assembled into an aqueous lithium-ion full battery, and were subjected to charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. The results indicate that the electrochemical performances of the three composites are significantly improved compared with the pure LiV3O8. Specifically, the discharge capacities of the two groups of nanorod-like composites were 112.2 mAh/g and 85.5 mAh/g at a rate of 0.2 C, which were improved by as much as two times compared with the pure LiV3O8. However, the composite material with layered structure not only reaches an initial discharge specific capacity of 148.39 mAh/g, which is 2.7 times higher than that of the pure LiV3O8, but also effectively slows down the dissolution effect of LiV3O8 by compositing with the carbon material, and at the same time, it shows excellent rate performance.

Li1.4Al0.4Ti1.6(PO4)3 coating surface modification enables improved electrochemical performance of LiNi0.83Co0.11Mn0.06O2 cathode

High-nickel ternary active materials with LiNi0.83Co0.11Mn0.06O2 (NCM83) have attracted extensive attention from researchers because of their exceptional performance and competitive pricing. Nevertheless, the actual large-scale uses of this material are restricted due to its limited lithium vacancies, residual lithium on the surface, and poor thermal stability. To improve the electrochemical performance of NCM83, an effective strategy for coating high ionic conductors of Li1.4Al0.4Ti1.6(PO4)3 (LATP) on NCM83 has been proposed. The uniform coatings of LATP are prepared by a wet coating process, which efficiently protects NCM83 from electrolyte attack, reduces internal stress, and improves the material’s thermal stability. Consequently, the cycle stability and thermal stability of the coated cathodes are significantly enhanced. Typically, 1 wt% LATP coating delivers a higher discharge specific capacity of 179.3 mAh g−1 at 2 C. The capacity retention rate is 69.67 % after 300 cycles at 1 C, higher than NCM83 (capacity retention rate of only 61.27 %). This study presents a new direction for researching high-nickel ternary cathode materials.

Constructing a Li–Zn lithiophilic layer by a scalable method of magnetron sputtering for a high-quality Li–B alloy anode

Lithium metal anodes offer high theoretical capacity and low redox potential but face challenges like dendritic growth, fragile solid electrolyte interface (SEI), "dead lithium" formation, and volume expansion. Composite anodes or artificial SEIs can address these issues, but often suffer from poor lithiophilicity and mass burdens. This study presents a Li–Zn–B alloy anode combining a Li–Zn lithiophilic layer with a bulk Li–B alloy. The Li–Zn lithiophilic layer, formed by magnetron sputtering of Zinc oxide (ZnO), improves surface lithiophilicity. Symmetrical cells with this alloy cycled stably for 1300 (1 mA cm−2, 1 mAh cm−2) and 550 h (2 mA cm−2, 2 mAh cm−2) with minimal overpotentials. The LiBZn||NCM811 full cell showed a specific discharge capacity of 130.8 mAh/g and stable Coulombic efficiency of 98.9 % after 300 cycles.

Lithium-Rich Porous Aromatic Framework Doped Quasi-Solid Polymer Electrolyte for Lithium Battery with High Cycling Stability.

Lithium-ion batteries (LIBs) have revolutionized the energy storage landscape and are the preferred power source for various applications, ranging from portable electronics to electric vehicles. The constant drive and growth in battery research and development aim to enhance their performance, energy density, and safety. Advanced lithium batteries (LIBs) are considered to be the most promising electrochemical storage devices, which can provide high specific energy, volumetric energy density, and power density. However, the trade-off between ionic conductivity and cycling stability is still a major contradiction for SPEs. In this work, a novel hydroxylated PAF-1 was designed and synthesized through post-modification, and the lithium-rich single-ion porous aromatic framework PAF-1-OLi was thereafter prepared by lithiation, achieved with a specific surface area to be 155 m2 g-1 and a lithium content of 2.01 mmol g-1. PAF-1-OLi, lithium bis(trifluoromethanesulfony)limine (LiTFSI), and poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) were compounded to obtain PAF-1-OLi/PVDF by solution casting, which had good mechanical, thermodynamic, and electrochemical properties. The ion conductivity of PAF-1-OLi/PVDF infiltrated with plasticizer was 2.93 × 10-4 S cm-1 at 25 °C. The tLi+ was 0.77, which was much higher than that of the traditional dual-ion polymer electrolytes. The electrochemical window of PAF-1-OLi/PVDF can reach 4.9 V. The Li//PAF-1-OLi/PVDF//LiFePO4 battery initial discharge specific capacity was 147 mAh g-1 and reached 134.9 mAh g-1 after 600 cycles with a capacity retention rate of 91.2%, demonstrating its good cycling stability. The anionic part of lithium salt was fixed on the framework of PAF-1 to increase the Li+ transfer number of PAF-1-OLi/PVDF. The lithium-rich PAF-1-OLi and the LiTFSI provided abundant Li+ sources to transfer, while PAF-1-OLi helped to form a continuous Li+ transport channel, effectively promoting the migration of Li+ in the PAF-1-OLi/PVDF and effectively improving the Li+ conductivity. This study afforded a novel polymer electrolyte based on lithium-rich PAF-1-OLi, which has excellent electrochemical performance, providing a new choice for the polymer electrolyte of lithium batteries.