Fast-Charging Phosphorus-Based Anodes: Promises, Challenges, and Pathways for Improvement.

Fast-charging batteries are highly sought after. However, the current battery industry has used carbon as the preferred anode, which can suffer from dendrite formation problems at high current density, causing failure after prolonged cycling and posing safety hazards. The phosphorus (P) anode is being considered as a promising successor to graphite due to its safe lithiation potential, low ion diffusion energy barrier, and high theoretical storage capacity. Since 2019, fast-charging P-based anodes have realized the goals of extreme fast charging (XFC), which enables a 10 min recharging time to deliver a capacity retention larger than 80%. Rechargeable battery technologies that use P-based anodes, along with high-capacity conversion-type cathodes or high-voltage insertion-type cathodes, have thus garnered substantial attention from both the academic and industry communities. In spite of this activity, there remains a rather sparse range of high-performance and fast-charging P-based cell configurations. Herein, we first systematically examine four challenges for fast-charging P-based anodes, including the volumetric variation during the cycling process, the electrode interfacial instability, the dissolution of polyphosphides, and the long-lasting P/electrolyte side reactions. Next, we summarize a range of strategies with the potential to circumvent these challenges and rationally control electrochemical reaction processes at the P anode. We also consider both binders and electrode structures. We also propose other remaining issues and corresponding strategies for the improvement and understanding of the fast-charging P anode. Finally, we review and discuss the existing full cell configurations based on P anodes and forecast the potential feasibility of recycling spent P-based full cells according to the trajectory of recent developments in batteries. We hope this review affords a fresh perspective on P science and engineering toward fast-charging energy storage devices.

Rational Molecular Engineering via Electron Reconfiguration toward Robust Dual-Electrode/Electrolyte Interphases for High-Performance Lithium Metal Batteries.

High-energy-density lithium-metal batteries (LMBs) coupling lithium-metal anodes and high-voltage cathodes are hindered by unstable electrode/electrolyte interphases (EEIs), which calls for the rational design of efficient additives. Herein, we analyze the effect of electron structure on the coordination ability and energy levels of the additive, from the aspects of intramolecular electron cloud density and electron delocalization, to reveal its mechanism on solvation structure, redox stability, as-formed EEI chemistry, and electrochemical performances. Furthermore, we propose an electron reconfiguration strategy for molecular engineering of additives, by taking sorbide nitrate (SN) additive as an example. The lone pair electron-rich group enables strong interaction with the Li ion to regulate solvation structure, and intramolecular electron delocalization yields further positive synergistic effects. The strong electron-withdrawing nitrate moiety decreases the electron cloud density of the ether-based backbone, improving the overall oxidation stability and cathode compatibility, anchoring it as a reliable cathode/electrolyte interface (CEI) framework for cathode integrity. In turn, the electron-donating bicyclic-ring-ether backbone breaks the inherent resonance structure of nitrate, facilitating its reducibility to form a N-contained and inorganic Li2O-rich solid electrolyte interface (SEI) for uniform Li deposition. Optimized physicochemical properties and interfacial biaffinity enable significantly improved electrochemical performance. High rate (10 C), low temperature (-25 °C), and long-term stability (2700 h) are achieved, and a 4.5 Ah level Li||NCM811 multilayer pouch cell under harsh conditions is realized with high energy density (462 W h/kg). The proof of concept of this work highlights that the rational ingenious molecular design based on electron structure regulation represents an energetic strategy to modulate the electrolyte and interphase stability, providing a realistic reference for electrolyte innovations and practical LMBs.

High-Efficiency Separator Capacity-Compensation Strategy Applied to Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are expected to replace partial reliance on lithium-ion batteries (LIBs) in the field of large-scale energy storage as well as low-speed electric vehicles due to the abundance, wide distribution, and easy availability of sodium metal. Unfortunately, a certain amount of sodium ions are irreversibly trapped in the solid electrolyte interface (SEI) layer during the initial charging process, causing the initial capacity loss (ICL) of the SIBs. A separator capacity-compensation strategy is proposed, where the capacity compensator on the separator oxidizes below the high cut-off voltage of the cathode to provide additional sodium ions. This strategy shows attractive advantages, including adaptability to current production processes, no impairment of cell long-cycle life, controlled pre-sodiation degree, and strategy universality. The separator capacity-compensation strategy is applied in the NaNi1/3 Fe1/3 Mn1/3 O2 (NMFO)||HC full cell and achieve a compensated capacity ratio of 18.2%. In the Na3 V2 (PO4 )3 (NVP)||HC full cell, the initial reversible specific capacity is increased from 61.0 mAh g-1 to 83.1 mAh g-1 . The separator capacity-compensation strategy is proven to be universal and provides a new perspective to enhance the energy density of SIBs.

Separator with Nitrogen-Phosphorus Flame-Retardant for LiNix Coy Mn1- x - y O2 Cathode-Based Lithium-Ion Batteries.

With the pursuit of high-energy-density for lithium-ion batteries (LIBs), the hidden safety problems of batteries have gradually emerged. LiNix Coy Mn1- x - y O2 (NCM) is considered as an ideal cathode material to meet the urgent needs of high-energy-density batteries. However, the oxygen precipitation reaction of NCM cathode at high temperature brings serious safety concerns. In order to promote high-safety lithium-ion batteries, herein, a new type of flame-retardant separator is prepared using flame-retardant (melamine pyrophosphate, MPP) and thermal stable Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). MPP takes the advantage of nitrogen-phosphorus synergistic effect upon the increased internal temperature of LIBs, including the dilution effect of noncombustible gas and the rapidly suppression of undesirable thermal runaway. The developed flame-retardant separators show negligible shrinkage over 200 °C and it takes only 0.54 s to extinguish the flame in the ignition test, which are much superior to commercial polyolefin separators. Moreover, pouch cells are assembled to demonstrate the application potential of PVDF-HFP/MPP separators and further verify the safety performance. It is anticipated that the separator with nitrogen-phosphorus flame-retardant can be extensively applied to various high-energy-density devices owing to simplicity and cost-effectiveness.

Lactobacillus plantarum-Derived Postbiotics Ameliorate Acute Alcohol-Induced Liver Injury by Protecting Cells from Oxidative Damage, Improving Lipid Metabolism, and Regulating Intestinal Microbiota.

Here, the aim was to evaluate the protective effect of Lactobacillus plantarum-derived postbiotics, i.e., LP-cs, on acute alcoholic liver injury (ALI). After preincubation with LP-cs, HL7702 human hepatocytes were treated with alcohol, and then the cell survival rate was measured. C57BL/6 male mice were presupplemented with or without LP-cs and LP-cs-loaded calcium alginate hydrogel (LP-cs-Gel) for 3 weeks and given 50% alcohol gavage to establish the mouse model of ALI, LP-cs presupplementation, and LP-cs-Gel presupplementation. The histomorphology of the liver and intestines; the levels of serum AST, ALT, lipid, and SOD activity; liver transcriptomics; and the metagenome of intestinal microbiota were detected in all mouse models. In vitro, LP-cs significantly increased the survival rate of alcohol-treated cells. In vivo, presupplementation with LP-cs and LP-cs-Gel restored the levels of serum AST, ALT, and SOD activity, as well as TC and TG, after acute alcohol intake. In the LP-cs-presupplemented mice, the genes involved in fatty acid metabolic processes were upregulated and the genes involved in steroid biosynthesis were downregulated significantly as compared with the ALI mice. LP-cs significantly increased the abundance of intestinal microbiota, especially Akkermansia muciniphila. In conclusion, LP-cs ameliorates ALI by protecting hepatocytes against oxidative damage, thereby, improving lipid metabolism and regulating the intestinal microbiota. The effect of LP-cs-Gel is similar to that of LP-cs.

Local Electric Field Promoted Kinetics and Interfacial Stability of a Phosphorus Anode with Ionic Covalent Organic Frameworks.

A phosphorus anode is a promising option for energy-storage applications because of its high theoretical specific capacity and safe lithiation potential. However, the multiphase phosphorus lithiation/delithiation reactions and soluble reaction intermediates cause sluggish reaction kinetics and loss of active materials. Herein, a novel local electric field (LEF) strategy is proposed to inhibit the intermediates dissolution and promote the reaction kinetics by optimizing ionic covalent organic frameworks (iCOFs). Among them, the LEF induced by the cationic covalent organic framework effectively enhances the electrochemical performance of the phosphorus anode. The strong electrostatic interaction between the polyphosphides and cationic covalent organic framework confines the dissolution of active materials and tailors the electronic structure of polyphosphides to accelerate the reaction kinetics. The cationic covalent-organic-framework-assisted phosphorus anode provides a high capacity of 1227.8 mAh g-1 at 10.4 A g-1 (8.6 C) and a high-capacity retention of 87% after 500 cycles at 1.3 A g-1 . This work not only broadens the application of iCOFs for phosphorus anode but also inspires the great potential of the local electric field in battery technology.

Inhibiting the Dissolution of Lithium Polyphosphides and Enhancing the Reaction Kinetics of a Phosphorus Anode via Screening Functional Additives.

A high-capacity, low-cost phosphorus anode is considered as one of the most promising candidates for next-generation Li-ion batteries. Nevertheless, the dissolution/shuttle effect of lithium polyphosphides and sluggish electrochemical conversion hinder the practical application of a phosphorus anode, similar to the problems of a sulfur cathode. Although the reported functional additives with physical obstruction and chemical adsorption have been successful in improving the performance of a sulfur cathode, they can not be directly applied to phosphorus due to their deterioration and failure in low voltage. To solve the above problems, we made a systematic investigation to rationally select the functional additives (Li2O, Li2S, and LiF) and effectively guide the experiment. These functional additives possess synergetic effects, including the adsorption of soluble lithium polyphosphides and the catalytic conversion of phosphorus species. The design of these functional additives provides a guiding and screening principle for inhibiting the dissolution of polyphosphides and improving the reaction kinetics of a phosphorus anode.

Nonsacrificial Nitrile Additive for Armoring High-Voltage LiNi0.83 Co0.07 Mn0.1 O2 Cathode with Reliable Electrode-Electrolyte Interface toward Durable Battery.

High-capacity Ni-rich layered oxides are considered as promising cathodes for lithium-ion batteries. However, the practical applications of LiNi0.83 Co0.07 Mn0.1 O2  (NCM83) cathode are challenged by continuous transition metal (TM) dissolution, microcracks and mixed arrangement of nickel and lithium sites, which are usually induced by deleterious cathode-electrolyte reactions. Herein, it is reported that those side reactions are limited by a reliable cathode electrolyte interface (CEI) layer formed by implanting a nonsacrificial nitrile additive. In this modified electrolyte, 1,3,6-Hexanetricarbonitrile (HTCN) plays a nonsacrificial role in modifying the composition, thickness, and formation mechanism of the CEI layers toward improved cycling stability. It is revealed that HTCN and 1,2-Bis(2-cyanoethoxy)ethane (DENE) are inclined to coordinate with the TM. HTCN can stably anchor on the NCM83 surface as a reliable CEI framework, in contrast, the prior decomposition of DENE additives will damage the CEI layer. As a result, the NCM83/graphite full cells with the LiPF6-EC/DEC-HTCN (BE-HTCN) electrolyte deliver a high capacity retention of 81.42% at 1 C after 300 cycles at a cutoff voltage of 4.5 V, whereas BE and BE-DENE electrolytes only deliver 64.01% and 60.05%. This nonsacrificial nitrile additive manipulation provides valuable guidance for developing aggressive high-capacity Ni-rich cathodes.