Initial Discharge Research Articles

Layered Polymer Stacking for Stable Interfaces and Dendrite Growth Inhibition in All-Solid-State Lithium Batteries.

To improve the ionic conductivity and cycling stability of solid-state lithium batteries based on poly(ethylene oxide) (PEO) electrolytes, we developed a sandwich-structured composite polymer electrolyte (sandwich-CPE) PEO-TiN/PEO-LiYF4/PEO-TiN. The sandwich-CPE delivers a high ionic conductivity of 1.7 × 10-4 S cm-1 at 30 °C and a wide potential window of 0 to 5.0 V (vs Li/Li+). Adding PEO-TiN leads to the formation of Li3N between Li and sandwich-CPE during cycling, which effectively reduces the level of Li dendrite formation. Additionally, PEO-TiN acts as a sacrificial layer to stop the entry of Li dendrites into the interlayer PEO-LiYF4. Using the sandwich-CPE, LiFePO4 retains a reversible capacity of 113.8 mA h g-1 at 30 °C after 300 cycles under 0.5 C. For high-voltage cells, LiNi0.5Co0.2Mn0.3O2 retains a capacity retention of 71.4% at 45 °C after 300 cycles under 0.2 C among 3.0-4.3 V, while Li3V2(PO4)3 delivers an initial discharge capacity of 108.1 mA h g-1 at 60 °C and retains 81.6% after 500 cycles under 1 C among 2.8-4.4 V. These results demonstrate the strong electrochemical compatibility of the sandwich-CPE, enabling high reversible capacity and good cycling stability for solid-state Li batteries with different cathodes at different temperatures and current rates.

Application of ZIF-67/ZIF-8 derived Co3O4/ZnO heterojunction in lithium-sulfur battery separators

Lithium-sulfur batteries (LSBs) have attracted widespread attention because of their advantages such as high discharge capacity and high energy density. Although LSBs have good development potential, there are still many obstacles, such as poor conductivity, volume expansion etc., especially shuttle effect which seriously limit the application of LSBs. To restrain the shuttle effect, we proposed a novel Co3O4/ZnO dodecahedral heterojunction as a separator blocking layer which was derived form ZIF-67/ZIF-8 bimetallic MOF. Since the bimetallic oxide heterojunction contains more abundant oxygen vacancies, it has better adsorption and catalytic performances than monometallic oxides. Co3O4/ZnO coated on the PE separator can effectively block the lithium polysulfides (LiPSs) shuttle due to its good adsorption ability, furthermore, the catalytic effect will accelerate the reaction of LiPSs and improve the electrochemical performances. Consequently, the initial discharge specific capacity of the Co3O4/ZnO modified separator battery at 0.5 C rate reaches up to 875.5 mAh g−1 when the cathode sulfur areal density is 3 mg cm−2, and still keep 500.9 mAh g−1 after 400 long cycles. Even when the cathode sulfur areal density is 5 mg cm−2, it still shows good cycle stability.

Rates and reasons for hospital readmission after acute ischemic stroke in a US population-based cohort.

Hospital readmissions following stroke are costly and lead to worsened patient outcomes. We examined readmissions rates, diagnoses at readmission, and risk factors associated with readmission following acute ischemic stroke (AIS) in a large United States (US) administrative database. Using the 2019 Nationwide Readmissions Database, we identified adults discharged with AIS (ICD-10-CM I63*) as the principal diagnosis. Survival analysis with Weibull accelerated failure time regression was used to examine variables associated with hospital readmission. In 2019, 273,811 of 285,451 AIS patients survived their initial hospitalization. Of these, 60,831 (22.2%) were readmitted within 2019. Based on Kaplan Meyer analysis, readmission rates were 9.7% within 30 days and 30.5% at 1 year following initial discharge. The most common causes of readmissions were stroke and post stroke sequalae (25.4% of 30-day readmissions, 15.0% of readmissions between 30-364 days), followed by sepsis (10.3% of 30-day readmissions, 9.4% of readmissions between 30-364 days), and acute renal failure (3.2% of 30-day readmissions, 3.0% of readmissions between 30-364 days). After adjusting for multiple patient and hospital-level characteristics, patients at increased risk of readmission were older (71.6 vs. 69.8 years, p<0.001) and had longer initial lengths of stay (7.6 vs. 6.2 day, p<0.001). They more often had modifiable comorbidities, including vascular risk factors (hypertension, diabetes, atrial fibrillation), depression, epilepsy, and drug abuse. Social determinants associated with increased readmission included living in an urban (vs. rural) setting, living in zip-codes with the lowest median income, and having Medicare insurance. All factors were significant at p<0.001. Unplanned hospital readmissions following AIS were high, with the most common reasons for readmission being recurrent stroke and post stroke sequalae, followed by sepsis and acute renal failure. These findings suggest that efforts to reduce readmissions should focus on optimizing secondary stroke and infection prevention, particularly among older socially disadvantaged patients.

Ce-Doped Three-Dimensional Ni/Fe LDH Composite as a Sulfur Host for Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSBs) have become the most promising choice in the new generation of energy storage/conversion equipment due to their high theoretical capacity of 1675 mAh g-1 and theoretical energy density of 2600 Wh kg-1. Nevertheless, the continuous shuttling of lithium polysulfides (LiPSs) restricts the commercial application of LSBs. The appearance of layered double hydroxides (LDH) plays a certain role in the anchoring of LiPSs, but its unsatisfactory electronic conductivity and poor active sites hinder its realization as a sulfur host for high-performance LSBs. In this paper, metal organic framework-derived and Ce ion-doped LDH (Ce-Ni/Fe LDH) with a hollow capsule configuration is designed rationally. The hollow structure of Ce-Ni/Fe LDH contains a sufficient amount of sulfur. Fe, Ni, and Ce metal ions effectively trap LiPSs; speed up the conversion of LiPSs; and firmly anchor LiPSs, thus effectively inhibiting the shuttle of LiPSs. The electrochemical testing results demonstrate that a lithium-sulfur battery with capsule-type S@Ce-Ni/Fe LDH delivers the initial discharge capacities of 1207 mAh g-1 at 0.1 C and 1056 mAh g-1 at 0.2 C, respectively. Even at 1 C, a lithium-sulfur battery with S@Ce-Ni/Fe LDH can also cycle 1000 times. This work provides new ideas to enhance the electrochemical properties of LSBs by constructing a hollow capsule configuration.

Discharge education and sepsis re admission An integrative review

Hospital readmission has long been a threat to our country’s healthcare system. Sepsis has recently become the number one disease condition resulting in readmissions following an initial inpatient hospital discharge. Increase in the number of sepsis survivors causes a huge burden to the healthcare system secondary to increased morbidity, mortality, utilization of health care resources, and transition to hospice. This integrative review explored the existing literature on the effect of post sepsis care education on reducing all cause readmission among sepsis survivors.

Separator modified by ternary iron molybdenum nitride and nitrogen-doped carbon composite enabling efficient polysulfide conversion for lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) are appealing energy storage systems by virtue of the high theoretical energy density and abundant resources of sulfur. However, the sluggish redox reaction kinetics and shuttle effect of soluble lithium polysulfides (LiPSs) seriously restrict their practical applications. Searching for highly efficient and low cost electrocatalysts towards LiPSs conversion is one of the most promising approaches to relieve the shuttle effect and enhance the sulfur utilization. In this work, we first demonstrate the application of ternary iron molybdenum nitride hybridized with nitrogen-doped carbon, denoted as (Fe0.81Mo0.19)MoN2/NC composite, as an advanced separator modifier to boost the bidirectional catalytic conversion of LiPSs. Impressively, the as-fabricated LSBs with (Fe0.81Mo0.19)MoN2/NC modified separator display an ultrahigh initial discharge capacity of 1366.1 mAh g−1 at 0.1 C and still remains a high value of 809.1 mAh g−1 at a high rate of 4 C. Furthermore, a remarkable discharge capacity of 569.2 mAh g−1 is retained when cycling at a high rate of 1 C for 700 cycles (corresponding to a low attenuation rate of 0.065 % per cycle), indicating the good long-term cycling stability. The excellent performance could be attributed to the multiple advantages of high electrical conductivity, numerous active sites, strong adsorption ability and excellent catalytic activity, thereby effectively suppressing the shuttle effect of LiPSs. The present work indicates that the ternary transition metal nitrides could be promising separator modifiers for high-performance LSBs.

Study of the Initiation of Arc Discharges by Separating Initially Closed Electrodes

Study of the Initiation of Arc Discharges by Separating Initially Closed Electrodes

Prebreakdown and Breakdown Behavior of Low Pour Point Dielectric Liquids Under Negative Lightning Impulse Voltage

In this paper, some investigations on the prebreakdown and breakdown phenomena of low pour point insulating liquids under negative lightning impulse voltage are reported. The tested liquids include mineral oil, a typical synthetic ester, and two low pour point synthetic esters. These liquids underwent accelerated thermal aging. The non-aged and aged samples were subjected to lightning impulses using a point-plane electrode arrangement. The discussions are focused on the initiation of partial discharges, propagation of streamers, and breakdown behaviour in the non-aged and aged liquids. The investigated parameters include inception voltage, lightning impulse breakdown voltage, streamer acceleration voltage, and streamer velocity. The results are supported by the oscillographs of the light activity that is recorded during the discharge process. The prebreakdown phenomenon noticed in the typical synthetic ester vis-à-vis mineral insulating oil is in line with the existing literature. Importantly, it is noticed that the inception and breakdown voltages of the non-aged low pour point synthetic esters are similar to non-aged mineral oil. In addition, the inception and breakdown voltages of the aged low pour point synthetic esters are noticed to be higher than that of the aged mineral oil. These results add to the arguments in favor of replacing mineral oils in power transformers.

Metal cation cross-linked 3D frameworks of Fe3O4 nanospheres encapsulated in graphene nanomesh with enhanced anode performance for lithium-ion batteries

Transition metal oxide (TMO) particles encapsulated in graphene shell has been reported to be an ideal lithium-ion batteries (LIBs) anode due to its well TMO particles volumetric adaptability upon cycling. In this paper, to further enhance the structural stability as well as electrochemical performance of Fe3O4-based electrodes for LIBs, 3D composite structures of Fe3O4 nanospheres (NSs) encapsulated in interconnected holey graphene nanosheets (Ca2+/p-rGO@Fe3O4) were fabricated by facile hydrothermal process using Ca2+ as crosslinker and hydrogen peroxide (H2O2) as etching agent. The composite was characterized by X-ray diffractometer (XRD), Scanning electron microscope (SEM), Transmission electron microscope (TEM), Fourier Transform Infrared Spectrometer (FTIR), and other test methods. The morphological and structural tests show that Fe3O4 NSs are homogenously embedded in the 3D framework of interconnected graphene nanomesh aerogels. Based on its unique structure, the Ca2+/p-rGO@Fe3O4 composite electrode delivers an initial discharge and charge capacities of 1288 and 783 mA h g−1, respectively, remarkable rate capability at current densities from 0.1 to 2 A g−1 and excellent cyclic stability with respect to that of its counterparts Ca2+/rGO@Fe3O4 electrode, p-rGO@Fe3O4 electrode and rGO@Fe3O4 electrode, which are prepared using a similar synthetic procedure but without the addition of H2O2 or CaCl2 or neither. It is proved that the synergistic effects of Ca2+-induced crosslinking reaction at the edge of GO nanosheets and in-plane pores on graphene coated on the surface of Fe3O4 can enhance the whole electrochemical performance of anode for LIBs.

Electrodeposited heterostructured manganese oxides on carbonized clothes for enhanced lithium polysulfides conversion as free-standing sulfur cathodes

Various metal oxides are investigated to catalyse lithium polysulfides (LiPS) conversion to promote the surface-bound insoluble intermediates and limit the LiPS shuttle. Herein, an effective methodology is reported to enhance LiPS catalytic conversion by applying electrodeposited hybrid phase composite films of manganese oxide (MnOx) on carbonized cotton cloth. Synergistic effects of porous carbon fabric with remnant lumen and high interfacial MnOx composite film of nanoflakes greatly contribute towards freestanding high-loaded sulfur cathodes. Various MnOx phases are realized by controlled annealing of MnOOH electrodeposited nanoflakes on carbon cloth. Oxygen deficient phases especially active interfaces among various phases are proposed to accelerate the LiPS oxidation to polythionate complexes that can interact with LiPS to assist their onsite conversion into sulfides. Pristine and LiPS interacted deposited films are investigated by X-ray photoelectron spectra and X-ray absorption spectra. The cathodes bearing high oxygen-deficient manganese oxide nanoflakes achieve high initial discharge capacity of 1153.7 mA h g−1 at 0.1 C and high reversible capacity of 824 mA h g−1 at 0.5 C over 200 cycles at sulfur areal loading of 5 mg cm−2, while initial discharge capacity of 1085.9 mA h g−1 and reversible capacity of 410 mA h g−1 are obtained for MnO2 rich heterostructure film.

Nitrogen-doped nanotubes and few-layer montmorillonite composites as an effective polysulfides adsorbent for lithium–sulfur batteries

With the advantages of high specific energy and high theoretical capacity, lithium‑sulfur batteries are gaining attention in the field of energy storage. However, there are still many difficulties in the practical application. Such as poor electrical conductivity of sulfur, large volume expansion of sulfur, shuttle effect of polysulfide, resulting in rapid capacity decay and poor cycling stability. To solve these problems, in this paper, nitrogen-doped carbon nanotube and layer less montmorillonite composites (NMMT/CNT/S) were prepared by a simple hydrothermal method and used as sulfur carriers for lithium‑sulfur batteries. Due to the high conductivity of carbon nanotubes, the high specific surface area and large number of adsorption sites in montmorillonite, and the ability of nitrogen to increase electrochemical reactivity, the obtained NMMT/CNT/S has excellent electrochemical performance: Initial discharge capacity up to 1122 mAh/g at a current density of 0.5C, initial specific capacity of 1017 mAh/g at a current density of 1C, capacity remaining after 100 cycles 815 mAh/g, the capacity retention rate is 80.1 %. The prepared NMMT/CNT/S cathode material has good magnification performance, at current densities of 0.2, 0.5, 1, 2 and 4C, the average specific capacity was 1085.9, 902.2, 820.4, 681.2 and 526.4 mAh/g, respectively. The initial specific capacity of NMMT/CNT/S at a current density of 2C is 698 mAh/g, capacity remaining 542 mAh/g after 500 cycles of stabilization, with a capacity retention rate of 77.7 %. These results show that the prepared NMMT/CNT/S is a breakthrough development in the application of lithium‑sulfur batteries.

CoNi-ZIF-derived NiCo2Se4-NC promotes polysulfide adsorption and reaction kinetics in high-performance lithium-sulfur batteries

In this study, NiCo2Se4-NC was synthesized by high-temperature carbonization of zeolitic imidazole skeleton (CoNi-ZIF) and solvothermal technique, and its polyhedral structure with prominent specific surface area and numerous pores effectively mitigated the effect of volume expansion. Similarly, the bimetallic Ni/Co synergy improves the adsorption of polysulfides by the cathode material, thus improving the electrochemical performance of the battery. Density function theory (DFT) and static adsorption experimental results indicate that NiCo2Se4-NC has excellent binding properties to polysulfides. NiCo2Se4-NC was tested electrochemically as the cathode material and had an excellent initial discharge capacity of 1393.7 mAhg−1 at 0.1 C. In addition, the initial discharging specific capacity was 841.6 mAhg−1 with a capacity retention of 79% at 450 cycles at 1 C current density, and the coulombic efficiency always ranged from 100% to 101.5%, indicating that NiCo2Se4-NC has good cycling stability and reversibility of the reaction.

In-situ embedding of ultrasmall MnO nanoparticles into pollen biomass-derived hollow porous N heteroatoms enriched carbon microspheres as high-performance anode for lithium-ion batteries

The transition manganese monoxide (MnO) is investigated as the one of the most promising candidates of anode nanomaterials for lithium-ion batteries (LIBs) due to its irreplaceable advantages of higher theoretical capacity, restricted voltage hysteresis and favorable electrochemical kinetics. Nevertheless, it still remains a big challenge to simultaneously resolve the nonideal properties of the relatively low dispersion of MnO, the structural metastability as well as the undesirable permeability of electrolyte. Herein, the ultrasmall MnO nanoparticles/sulfuric-acid-pretreated camellia pollen carbon (MnO/SCPC) composites are successfully fabricated by a facile bio-templating method of carbonization hydrolysis of camellia pollen, wet-impregnation treatment of Mn/SCPC precursor and followed by thermal annealing, which delivers hollow porous microspheres structure where the shell components are formed by orderly stacking of multiple ultrasmall-size MnO-loaded nanocarbon spheres. This advantageous nano-structures not only allow for a large volume change during the lithiation/delithiation process, a large accessible contact area with electrolyte and a short transport path for Li+ ions, but also enhance the amounts of electrochemically active sites while simultaneously endow them with a superior structural stability through robust interfacial interaction. These clever designs enable the MnO/SCPC composites to perform exceptionally well electrochemically. More specifically, the MnO/SCPC-600 anode possesses a high initial discharge capacity (1490 mAh·g−1) at a current density of 0.1 A·g−1, and still retains 60% of the initial capacity (894 mAh·g−1) after 100 cycles. Besides, it also exhibits a high discharge capacity of 612 mAh·g−1 at a current density of 2.0 A·g−1 and an ultralong cycling life of 584 mAh·g−1 at 1.0 A·g−1 for long period of 1000 cycles. This work also paves up a facile direction for the application of MnO/biomass-derived carbonaceous nanomaterials in LIBs.

Preparation of CoO-CoP-CNT heterogeneous materials for advanced lithium-sulfur battery cathode electrode

A one-dimensional linear material (CoO-CoP-CNT) was successfully prepared and studied as a sulfur-loaded material for the cathode. This heterostructure material exhibits a high specific surface area (115.29 m2 g−1) and rich active sites, which effectively suppress the volume expansion of sulfur and enhance the catalysis and adsorption of LiPS. As a result, it mitigates the shuttle effect of LiPS and improves the electrochemical performance of the battery. The initial discharge capacity of the battery employing the sulfur carrier was measured at 979.9 mAh g−1 at 0.2 C, and it demonstrated a capacity of 367.9 mAh g−1 after 200 cycles of charging and discharging. At 2 C, the initial discharge capacity of S/CoO-CoP-CNT reached 743.7 mAh g−1, with a capacity retention rate of 42.0% after 500 cycles. These findings indicate that the battery with S/CoO-CoP-CNT positive electrode exhibits superior electrochemical performance.

Bi-layered calcium vanadium oxide as a cathode material for wet organic electrolyte-based rechargeable Zn-ion batteries

Zn-ion batteries attract considerable attention as a promising option for large-scale energy storage owing to their many benefits, including safety, high abundance of zinc, low fabrication costs, and ease of handling in air. However, to improve their effectiveness, three key technical challenges must be overcome: low electrolyte performance, metal dendrite formation, and a limited choice of host materials. This study introduces a new cathode material for Zn-ion batteries — double-layered Ca0.26V2O5·H2O — that exhibits outstanding performance in a wet organic electrolyte. The cathode material demonstrates an initial discharge capacity of 268.76 mAh g−1 at a rate of 0.2C and average operating voltage of 0.82 V (vs. Zn2+/Zn) with excellent capacity retention. A reversible Zn intercalation/crystal water extraction reaction is confirmed by conducting elemental and structural analyses, including powder X-ray diffraction. Furthermore, the results of bond valence sum calculations support the formation of a two-dimensional network of Zn-ion conduction pathways along the a-axis and b-axis, illustrating the electrochemical zinc intercalation into the wet organic electrolyte. Overall, this study not only introduces double-layered Ca0.26V2O5·H2O as a new cathode material for Zn-ion batteries but also provides valuable insights into the electrochemical zinc intercalation/crystal water extraction in wet organic electrolytes.

NiCo-MOFs porous nanomaterials prepared by different organic frameworks as anodes for li-ion batteries

With the upgrading of mobile and portable electronic devices, people have higher requirements for the performance of batteries, and anode materials, as one of the factors affecting the electrochemical performance of lithium ion storage, have become a hot spot of widespread concern. This paper illustrates a creative and effective strategy to synthesize four different NiCo-MOFs materials. After studying their respective unique structural features, it was found that, unlike the topologies of NiCo-PTA (terephthalic acid) and NiCo-H3BTC (trimesic acid), the substitution of Ni and Co for N occurred in NiCo-EDTA (ethylenediaminetetraacetic acid) and NiCo-BI (benzimidazole). Electrochemical studies show that NiCo-PTA, NiCo-EDTA, NiCo-H3BTC, and NiCo-BI all have high initial discharge specific capacities of 1770.41576.11905.1 and 1877.5 mAh/g at a current density of 100 mA/g. When NiCo-EDTA and NiCo-BI are cycled at a current density of 100 mA/g, the specific capacity decreases more slowly than NiCo-PTA and NiCo-H3BTC. Similarly, the capacity of NiCo-PTA and NiCo-H3BTC almost began to rise at the 70th cycle, the capacity of NiCo-BI began to rise at the 67th cycle, and NiCo-EDTA showed the slowest rise at the 78th cycle, they all showed excellent cycle performance.

Fine phase adjustment optimizes structure stability and sodium ion diffusion ability of Na0.6Mn0.67–xNi0.22Fe0.11+xO2 via chemical environment variation

In this work, Na0.6Mn0.67−xNi0.22Fe0.11+xO2 (x = 0, 0.05, 0.1, 0.15) cathode materials were synthesized by a simple solid-state method, and the influence of Fe/Mn ratio on its fine phase structure and electrochemical performance was emphatically investigated. Firstly, XRD Rietveld refinement demonstrates that proportion of P2 phase and the distance between Na layers increases via increase of Fe/Mn ratio, which is beneficial to improve the diffusion rate of sodium ions. Secondly, reduced proportion of Mn3+ and Ni3+ in the material with the increase of Fe/Mn ratio is verified via XPS data analysis, which weakens Jahn-Teller effect and improves the cyclic stability of the material. Among them, the designed Na0.6Mn0.62Ni0.22Fe0.16O2 exhibits the initial discharge specific capacity 139 mAh g-1 at 0.5 C. The reversible specific capacity of 95 mAh g-1 can be maintained even at a higher current density of 2 C. The high electrochemical performance can be contributed to the lower charge transfer resistance and the higher sodium ion diffusion coefficient, which are evidenced by EIS and GITT analysis.

Morphology Engineering of VS4 Microspheres as High-Performance Cathodes for Hybrid Mg2+/Li+ Batteries.

V-based sulfides are considered as potential cathode materials for Mg2+/Li+ hybrid ion batteries (MLIBs) due to their high theoretical specific capacities, unique crystal structure, and flexible valence adjustability. However, the formation of irreversible polysulfides, poor cycling performance, and severe structural collapse at high current densities impede their further development. Herein, VS4 microspheres with various controllable nanoarchitectures were successfully constructed via a facile solvothermal method by adjusting the amount of hydrochloric acid and were used as cathode materials for MLIBs. The VS4 microsphere self-assembled by bundles of paralleled-nanorods and some intersected-nanorods (VS4@NC-5) exhibits an outstanding initial discharge capacity of 805.4 mAh g-1 at 50 mA g-1 that is maintained at 259.1 mAh g-1 after 70 cycles. Moreover, the VS4@NC-5 cathode can deliver a superior rate capability (146.1 mAh g-1 at 2000 mA g-1) and ultralong cycling life (134.5 mAh g-1 at 2000 mA g-1 after 2000 cycles). The extraordinary electrochemical performance of VS4@NC-5 could be attributed to its special multi-hierarchical microsphere structure and the formation of N-doped carbon layers and V-C bonds, resulting in unobstructed ion diffusion channels, multidimensional electron transfer pathways, and enhancements of electrical conductivity and structure stability. Furthermore, the electrochemical reaction mechanism and phase conversion behavior of the VS4@NC-5 cathode at various states are investigated by a series of ex situ characterization methods. The VS4 well-designed through morphological engineering in this work can pave a way to explore more sulfides with high-rate performance and long cycling stability for energy storage devices.

Synergetic effect of Ti-Mg-Sb tri-doping on enhanced electrochemical performance of LiCoO2 at 4.6 V

With a theoretical specific capacity of 274 mAh·g−1, LiCoO2 (LCO) is the favored cathode material for lithium ion batteries (LIBs) applied to electronic devices. However, the unfavorable transitions in phase of LCO structure at high voltage and the negative reactions occurring at the interface between cathode and electrolyte limit the practical applications of LCO. Therefore, we designed a novel tri-doping strategy to enhance the electrochemical performance of LCO at 4.6 V. The introduction of minimal quantities of Ti, Mg, and Sb to the transition metal (TM) layer of LCO resulted in a substantial increase in both the cycling stability and reversible capacity of LCO. The distribution of the doping elements in the modified LCO was also analyzed, and we found that Ti, Sb were uniformly distributed in the particles, while Mg tended to distribute at the near-surface area of the primary particles. Through the trace Ti-Mg-Sb tri-doping, the modified LCO cathode material can reach an initial discharge capacity of 222.9 mAh·g−1 between 3.0 and 4.6 V at 0.5 C with the capacity retention of 85.1% after 100 cycles. Moreover, the reversible capacity reached 114 mAh·g−1 at 10 C. This research offers a promising future for the development of 4.6 V LCO, as well as valuable insight into designing subsequently multi-element co-doping schemes for LCO cathodes.

A novel three-dimensional hierarchical porous lead-carbon composite prepared from corn stover for high-performance lead-carbon batteries

In this work, a novel three-dimensional(3D) hierarchical porous lead-carbon composite (Nano-PbO@3DCSHPAC) derived from corn stover biomass was prepared by chemical deposition coupled with pyrolysis to alleviate the problems associated with the high occurrence of the hydrogen evolution reaction (HER) and irreversible sulfation of the negative electrode under a high-rate partial state of charge (HRPSoC). As an additive of negative electrode in lead-carbon battery. PbO, evenly distributed on the Nano-PbO@3DCSHPAC composite, effectively inhibits the HER, acting as a nucleus for the active substance Pb, refining the grains of sponge Pb, and maintaining the high electrochemical active area of the electrode. The Nano-PbO@3DCSHPAC composite with a high specific surface area and porosity possesses good ion channels, provides an ion reservoir, and effectively inhibits irreversible sulfation. As a result, the initial discharge capacity of the battery with Nano-PbO@3DCSHPAC (164 mAh·g-1) is greater than that of the blank battery (109 mAh·g-1). The cycling life of the Nano-PbO@3DCSHPAC battery (10120 cycles) is 9.4 times that of a blank battery (1073 cycles). Our work provides insights into how to regulate the specific surface area and porosity of lead-carbon additives and makes full use of biomass straw to provide new ideas for solving the environmental problems caused by straw incineration. It is the embodiment of the circular economy.