Constructing a Cr-Substituted Co-Free Li-Rich Ternary Cathode with a Spinel-Layered Biphase Interface.

Lithium-rich manganese-based layered oxides (LRMOs) have recently attracted enormous attention on account of their remarkably big capacity and high working voltage. However, some inevitable inherent drawbacks impede their wide-scale commercial application. Herein, a kind of Cr-containing Co-free LRMO with a topical spinel phase (Li1.2Mn0.54Ni0.13Cr0.13O2) has been put forward. It has been found that the high valence of Cr6+ can reduce the Li+ ion content and induce the formation of a local spinel phase by combining more Li+ ions, which is beneficial to eliminate the phase boundary between the spinel phase and the bulk phase of the LRMO material, thus dramatically avoiding phase separation during the cycling process. In addition, the introduction of Cr can also expand the layer spacing and construct a stronger Cr-O bond compared with Mn-O, which enables to combine the transition metal (TM) slab to prevent the migration of TM ions and the transformation of the bulk phase to the spinel phase. Simultaneously, the synergistic effect of the successfully constructed spinel-layered biphase interface and the strong Cr-O bond can effectively impede the escape of lattice oxygen during the initial activation process of Li2MnO3 and provide the fast diffusion path for Li+ ion transmission, thus further reinforcing the configurable stability. Besides, Cr-LRMO presents an ultrahigh first discharge specific capacity of 310 mAh g-1, an initial Coulombic efficiency of as high as 92.09%, a good cycling stability (a capacity retention of 94.70% after 100 cycles at 1C), and a small voltage decay (3.655 mV per cycle), as well as a good rate capacity (up to 165.88 mAh g-1 at 5C).

Modulating Surface Architecture and Electronic Conductivity of Li-rich Manganese-Based Cathode.

Li-rich manganese-based cathode (LRMC) has attracted intense attention to developing advanced lithium-ion batteries with high energy density. However, LRMC is still plagued by poor cyclic stability, undesired rate capacity, and irreversible oxygen release. To address these issues, herein, a feasible polyvinylidene fluoride (PVDF)-assisted interface modification strategy is proposed for modulating the surface architecture and electronic conductivity of LRMC by intruding the F-doped carbon coating, spinel structure, and oxygen vacancy on the LRMC, which can greatly enhance the cyclic stability and rate capacity, and restrain the oxygen release for LRMC. As a result, the modified material delivers satisfactory cyclic performance with a capacity retention of 90.22% after 200 cycles at 1 C, an enhanced rate capacity of 153.58 mAh g-1 at 5 C and 126.32 mAh g-1 at 10 C, and an elevated initial Coulombic efficiency of 85.63%. Moreover, the thermal stability, electronic conductivity, and structure stability of LRMC are also significantly improved by the PVDF-assisted interface modification strategy. Therefore, the strategy of simultaneously modulating the surface architecture and the electronic conductivity of LRMC provides a valuable idea to improve the comprehensive electrochemical performance of LRMC, which offers a promising reference for designing LRMC with high electrochemical performance.

Reversible Oxygen Redox Chemistry in High-Entropy P2-Type Manganese-Based Cathodes via Self-Regulating Mechanism.

The irreversible oxygen-redox reactions in the high-voltage region of sodium-layered cathode materials lead to poor capacity retention and structural instability during cycling, presenting a significant challenge in the development of high-energy-density sodium-ion batteries. This work introduces a high-entropy design for layered Na0.67Li0.1Co0.1Cu0.1Ni0.1Ti0.1Mn0.5O2 (Mn-HEO) cathode with a self-regulating mechanism to extend specific capacity and energy density. The oxygen redox reaction was activated during the initial charging process, accompanied by the self-regulation of active elements, enhancing the ionic bonds to form a vacancy wall near the TM vacancies and thus preventing the migration of transition metal elements. Systematic in situ/ex situ characterizations and theoretical calculations comprehensively support the understanding of the self-regulation mechanism of Mn-HEO. As a result, the Mn-HEO cathode exhibits a stable structure during cycling. It demonstrates almost zero strain within a wide voltage range of 2.0-4.5 V with a remarkable specific capacity (177 mAh g-1 at 0.05 C) and excellent long-term cycling stability (87.6% capacity retention after 200 cycles at 2 C). This work opens a new pathway for enhancing the stability of oxygen-redox chemistry and revealing a mechanism of crystal structure evolution for high-energy-density layered oxides.

A novel ACE inhibitory peptide from Pelodiscus sinensis Wiegmann meat water-soluble protein hydrolysate.

Pelodiscus sinensis meat is a nutritional food and tonic with angiotensin-converting enzyme (ACE) inhibitory activities. To identify the bioactive substances responsible, several bioinformatics methods were integrated to enable a virtual screening for bioactive peptides in proteins identified within a water-soluble protein fraction of Pelodiscus sinensis meat by Shotgun proteomics. The peptides were generated from the identified proteins by in silico proteolysis using six proteases. A comparison of the numbers of proteins suitable for digestion with each enzyme and the iBAQ (intensity-based absolute quantification) values for these proteins revealed that bromelain and papain were the most suitable proteases for this sample. Next, the water solubility, toxicity, and ADMET (absorption/distribution/metabolism/excretion/toxicity) properties of these peptides were evaluated in silico. Finally, a novel ACE inhibitory peptide IEWEF with an IC50 value of 41.33 µM was identified. The activity of the synthesized peptide was verified in vitro, and it was shown to be a non-competitive ACE inhibitor. Molecular docking revealed that IEWEF could tightly bind to C-ACE, and N-ACE with energies less than 0 kJ mol-1, and the peptide IEWEF can form hydrogen bonds with C-ACE and N-ACE respectively. These results provide evidence that bioactive peptides in the water-soluble protein fraction account for (at least) some of the ACE inhibitory activities observed in Pelodiscus sinensis meat. Furthermore, our research provides a workflow for the efficient identification of novel ACE inhibitory peptides from complex protein mixtures.

Synergistic electrochemical catalysis by high-entropy metal phosphide in lithium-sulfur batteries.

The shuttle effect and sluggish redox kinetics of polysulfides have hindered the development of lithium-sulfur batteries (LSBs) as premier energy storage devices. To address these issues, a high-entropy metal phosphide (NiCoMnFeCrP) was synthesized using the sol-gel method. NiCoMnFeCrP, with its rich metal species, exhibits strong synergistic effects and provides numerous catalytic active sites for the conversion of polysulfides. These active sites, possessing significant polarity, can bond with polysulfides. In situ ultraviolet-visible were conducted to monitor the dynamic changes in species and concentrations of polysulfides, validating the ability of NiCoMnFeCrP to facilitate the conversion of polysulfides. The batteries with the NiCoMnFeCrP catalyst as functional separators exhibited minimal capacity decay rates of 0.04 % and 0.23 % after 100 cycles at 0 °C and 60 °C, respectively. This indicates that the NiCoMnFeCrP catalyst possesses good thermal stability. Meanwhile, its area capacity can reach 4.78 mAh cm-2 at a high sulfur load of 4.54 mg cm-2. In conclusion, NiCoMnFeCrP achieves the objective of mitigating the shuttle effect and accelerating the kinetics of the redox reaction, thereby facilitating the commercialization of LSBs.

Construction and catalysis role of a kinetic promoter based on lithium-insertion technology and proton exchange strategy for lithium-sulfur batteries.

The high theoretical energy density and specific capacity of lithium-sulfur (Li-S) batteries have garnered considerable attention in the prospective market. However, ongoing research on Li-S batteries appears to have encountered a bottleneck, with unresolved key technical challenges such as the significant shuttle effect and sluggish reaction kinetics. This investigation explores the catalytic efficacy of three catalysts for Li-S batteries and elucidates the correlation between their structure and catalytic impacts. The results suggest that the combined utilization of lithium-insertion technology and a proton exchange approach for δ-MnO2 can optimize its electronic structure, resulting in an optimal catalyst (H/Li inserted δ-MnO2, denoted as HLM) for the sulfur reduction reaction. The replacement of Mn sites in δ-MnO2 with Li atoms can enhance the structural stability of the catalyst, while the introduction of H atoms between transition metal layers contributes to the satisfactory catalytic performance of HLM. Theoretical calculations demonstrate that the bond length of Li2S4 adsorbed by the HLM molecule is elongated, thereby facilitating the dissociation process of Li2S4 and enhancing the reaction kinetics in Li-S batteries. Consequently, the Li-S battery utilizing HLM as a catalyst achieves a high areal specific capacity of 4.2 mAh cm-2 with a sulfur loading of 4.1 mg cm-2 and a low electrolyte/sulfur (E/S) ratio of 8 µL mg-1. This study introduces a methodology for designing effective catalysts that could significantly advance practical developments in Li-S battery technology.

Concentration-Gradient Structural LiFe0.5Mn0.5PO4/C Prepared via Co-precipitation Reaction for Advanced Lithium-Ion Batteries.

The intrinsically low electronic conductivity and slow ion diffusion kinetics limit further development of olivine LiFexMn1-xPO4 cathode materials. In this paper, with the aim of improving the performance of such materials and alleviating the Jahn-Taller effect of Mn3+ ion, a bimetallic oxalate precursor with gradient distribution of elemental concentration followed with an efficient process is applied to synthesize LiFe0.5Mn0.5PO4 nanocomposite. The results shown that with certain structural modulation of the precursor, the discharge capacity of synthesized LiFe0.5Mn0.5PO4 increased from 149 mAh g-1 to 156 mAh g-1 at 0.1 C, the cycling capacity was also remarkably improved. the Fe0.5Mn0.5C2O4 ⋅ 2H2O-1 precursor with gradient distribution of elemental concentration effectively restricts the reaction between electrode material and electrolyte, thereby alleviates the dissolution of Mn3+ ion, reduces the decay of capacity and improves the stability of the material.

Enabling Rapid and Stable Sodium Storage via a P2-Type Layered Cathode with High-Voltage Zero-Phase Transition Behavior.

Currently, a major target in the development of Na-ion batteries is the concurrent attainment of high-rate capacity and long cycling stability. Herein, an advanced Na-ion battery with high-rate capability and long cycle stability based on Li/Ti co-doped P2-type Na0.67Mn0.67Ni0.33O2, a host material with high-voltage zero-phase transition behavior and fast Na+ migration/conductivity during dynamic de-embedding process, is constructed. Experimental results and theoretical calculations reveal that the two-element doping strategy promotes a mutually reinforcing effect, which greatly facilitates the transfer capability of Na+. The cation Ti4+ doping is a dominant high voltage, significantly elevating the operation voltage to 4.4 V. Meanwhile, doping Li+ shows the function in charge transfer, improving the rate performance and prolonging cycling lifespan. Consequently, the designed P2-Na0.75Mn0.54Ni0.27Li0.14Ti0.05O2 cathode material exhibits discharge capacities of 129, 104, and 85 mAh g- 1 under high voltage of 4.4 V at 1, 10, and 20 C, respectively. More importantly, the full-cell delivers a high initial capacity of 198 mAh g-1 at 0.1 C (17.3 mA g-1) and a capacity retention of 73% at 5 C (865 mA g-1) after 1000 cycles, which is seldom witnessed in previous reports, emphasizing their potential applications in advanced energy storage.

P2/O3 Biphasic Cathode Material through Magnesium Substitution for Sodium-Ion Batteries.

P2-type Fe-Mn-based oxides offer excellent discharge specific capacity and are as affordable as typical layered oxide cathode materials for sodium-ion batteries (SIBs). After Cu modification, though they can improve the cycling performance and air stability, the discharge specific capacity will be reduced. Considering the complementary nature of biphasic phases in electrochemistry, hybridizing P2/O3 hybrid phases can enhance both the storage performance of the battery and specific capacity. Herein, a hybrid phase composite with high capacity and good cycle performance is deliberately designed and successfully prepared by controlling the amount of Mg doping in the layered oxide. It has been found that the introduction of Mg can activate anion redox in the oxide layer, resulting in a significant increase in the specific discharge capacity of the material. Meanwhile, the dual-phase structure can produce an interlocking effect, thus effectively alleviating structure strain. The degradation of cycling performance caused by structural damage during the high-voltage charging and discharging process is clearly mitigated. The results show that the specific discharge capacity of Na0.67Cu0.2Mg0.1Fe0.2Mn0.5O2 is as high as 212.0 mAh g-1 at 0.1C rate and 186.2 mAh g-1 at 0.2C rate. After 80 cycles, the capacity can still maintain 88.1%. Moreover, the capacity and cycle performance as well as the stability can still remain stable even in the high-voltage window. Therefore, this work offers an insightful exploration for the development of composite cathode materials for SIBs.

Sustained Release-Driven Interface Engineering Enables Fast Charging Lithium Metal Batteries.

LiNO3 has attracted intensive attention as a promising electrolyte additive to regulate Li deposition behavior as it can form favorable Li3N, LiNxOy species to improve the interfacial stability. However, the inferior solubility in carbonate-based electrolyte restricts its application in high-voltage Li metal batteries. Herein, an artificial composite layer (referred to as PML) composed of LiNO3 and PMMA is rationally designed on Li surface. The PML layer serves as a reservoir for LiNO3 release gradually to the electrolyte during cycling, guaranteeing the stability of SEI layer for uniform Li deposition. The PMMA matrix not only links the nitrogen-containing species for uniform ionic conductivity but also can be coordinated with Li for rapid Li ions migration, resulting in homogenous Li-ion flux and dendrite-free morphology. As a result, stable and dendrite-free plating/stripping behaviors of Li metal anodes are achieved even at an ultrahigh current density of 20 mA cm-2 (>570 h) and large areal capacity of 10 mAh cm-2 (>1200 h). Moreover, the Li||LiFePO4 full cell using PML-Li anode undergoes stable cycling for 2000 cycles with high-capacity retention of 94.8%. This facile strategy will widen the potential application of LiNO3 in carbonate-based electrolyte for practical LMBs.

One-step dilation technique in minimally invasive percutaneous nephrolithotomy / 中国内镜杂志

Objective To evaluate the efficacy and safety of one-step dilation technique in minimally invasive percutaneous nephrolithotomy (MPCNL). Methods Clinical data of 2813 patients who underwent MPCNL by one-step dilation technique from February 2011 to March 2015 was retrospectively analyzed. Results 2813 patients were successfully underwent MPCNL by one-step dilation, including 2383 cases who were accessed by single tracts (84.71%) and 430 (15.29%) cases by multiple tracts. The mean operating time was (78.6 ± 41.1) min, the mean tract accessing time was (2.3 ± 0.8) min.The stone-free rate after one session operation was 78.59%. It improved to 91.50% one month after operation. During and after operation, 93 cases needed transfusion, 21 underwent selective renal artery embolization. Adjacent viscera damage: 9 cases with pleural lesions and 1 case with colon injury, 13 cases with urinary extravasation, perirenal hematoma in 15 cases, without liver and spleen injury. Septic shock in 2 cases, who was recovered after anti-infection treatment. Conclusion One-step dilation is safe and effective technique to establish tracts in MPCNL, which can reduce X-ray exposure and operation time, but does not increase the risk of bleeding.

One-step dilation technique in minimally invasive percutaneous nephrolithotomy / 中国内镜杂志

Objective To evaluate the efficacy and safety of one-step dilation technique in minimally invasive percutaneous nephrolithotomy (MPCNL). Methods Clinical data of 2813 patients who underwent MPCNL by one-step dilation technique from February 2011 to March 2015 was retrospectively analyzed. Results 2813 patients were successfully underwent MPCNL by one-step dilation, including 2383 cases who were accessed by single tracts (84.71%) and 430 (15.29%) cases by multiple tracts. The mean operating time was (78.6 ± 41.1) min, the mean tract accessing time was (2.3 ± 0.8) min.The stone-free rate after one session operation was 78.59%. It improved to 91.50% one month after operation. During and after operation, 93 cases needed transfusion, 21 underwent selective renal artery embolization. Adjacent viscera damage: 9 cases with pleural lesions and 1 case with colon injury, 13 cases with urinary extravasation, perirenal hematoma in 15 cases, without liver and spleen injury. Septic shock in 2 cases, who was recovered after anti-infection treatment. Conclusion One-step dilation is safe and effective technique to establish tracts in MPCNL, which can reduce X-ray exposure and operation time, but does not increase the risk of bleeding.