First-Principles Calculations of TiB4 and TiB5 as Anodes with High Capacity for Na-Ion Batteries.

The electrochemical properties of TiB4 and TiB5 monolayers in Na-ion batteries (NIBs) were studied by using the first-principles calculation method based on density functional theory. The TiB4/TiB5 monolayer showed excellent Na storage capacity, capable of adsorbing two layers of Na with theoretical capacities of 1176.77 and 1052.05 mA g-1, respectively. The average operating voltages of the TiB4 and TiB5 monolayers are 0.073 and 0.042 eV, respectively, indicating that they can be used as anode materials for NIBs. More interestingly, the exposed B surface not only brings a high theoretical capacity but also provides a relatively small diffusion barrier of 0.16 (for TiB4) and 0.33 eV (for TiB5), enhancing their rate capability in NIBs.

Unlocking the Power of Magnesium Batteries: Synergistic Effect of InSb-C Composites to Achieve Superior Electrochemical Performance.

Pure magnesium anode used in rechargeable magnesium batteries (RMB) exhibits high theoretical capacity but has been challenged by the passivation issue with conventional electrolytes. Alloy-type anodes have the potential to surpass this issue and have attracted increasing attention. However, the kinetic performance and stabilities of conventional alloy anodes are still constrained. In this study, the InSb-10%C anode is synthesized by a two-step high-energy ball milling process. The InSb-10%C anode exhibits a remarkably high capacity of up to 448 mA h g-1, significantly improved cycle performance (234 mA h g-1 at 100 cycles) and rate performance (168 mA h g-1 at 500 mA g-1). The above-mentioned superior performance of the InSb-10%C anode for RMBs is attributed to the cellular graphitized amorphous carbon composite structure (CGA) which effectively refines the particle size and restricts the volume expansion. Additionally, the reduced surface electron density of InSb combined with the high conductivity resulting from graphitization enhances the Mg2+ diffusion performance. Notably, the InSb-10%C anode demonstrates good compatibility with conventional halogen-free salt ether-based electrolytes in the full battery configuration.

Dual-Defect Engineering Strategy Enables High-Durability Rechargeable Magnesium-Metal Batteries.

Rechargeable magnesium-metal batteries (RMMBs) are promising next-generation secondary batteries; however, their development is inhibited by the low capacity and short cycle lifespan of cathodes. Although various strategies have been devised to enhance the Mg2+ migration kinetics and structural stability of cathodes, they fail to improve electronic conductivity, rendering the cathodes incompatible with magnesium-metal anodes. Herein, we propose a dual-defect engineering strategy, namely, the incorporation of Mg2+ pre-intercalation defect (P-Mgd) and oxygen defect (Od), to simultaneously improve the Mg2+ migration kinetics, structural stability, and electronic conductivity of the cathodes of RMMBs. Using lamellar V2O5·nH2O as a demo cathode material, we prepare a cathode comprising Mg0.07V2O5·1.4H2O nanobelts composited with reduced graphene oxide (MVOH/rGO) with P-Mgd and Od. The Od enlarges interlayer spacing, accelerates Mg2+ migration kinetics, and prevents structural collapse, while the P-Mgd stabilizes the lamellar structure and increases electronic conductivity. Consequently, the MVOH/rGO cathode exhibits a high capacity of 197 mAh g-1, and the developed Mg foil//MVOH/rGO full cell demonstrates an incredible lifespan of 850 cycles at 0.1 A g-1, capable of powering a light-emitting diode. The proposed dual-defect engineering strategy provides new insights into developing high-durability, high-capacity cathodes, advancing the practical application of RMMBs, and other new secondary batteries.

H2O-Mg2+ Waltz-Like Shuttle Enables High-Capacity and Ultralong-Life Magnesium-Ion Batteries.

Mg-ion batteries (MIBs) are promising next-generation secondary batteries, but suffer from sluggish Mg2+ migration kinetics and structural collapse of the cathode materials. Here, an H2O-Mg2+ waltz-like shuttle mechanism in the lamellar cathode, which is realized by the coordination, adaptive rotation and flipping, and co-migration of lattice H2O molecules with inserted Mg2+, leading to the fast Mg2+ migration kinetics, is reported; after Mg2+ extraction, the lattice H2O molecules rearrange to stabilize the lamellar structure, eliminating structural collapse of the cathode. Consequently, the demo cathode of Mg0.75V10O24·nH2O (MVOH) exhibits a high capacity of 350 mAh g-1 at a current density of 50 mA g-1 and maintains a capacity of 70 mAh g-1 at 4 A g-1. The full aqueous MIB based on MVOH delivers an ultralong lifespan of 5000 cycles The reported waltz-like shuttle mechanism of lattice H2O provides a novel strategy to develop high-performance cathodes for MIBs as well as other multivalent-ion batteries.

Large-Scale Integration of the Ion-Reinforced Phytic Acid Layer Stabilizing Magnesium Metal Anode.

Rechargeable magnesium batteries (RMBs) have garnered significant attention for their potential in large-scale energy storage applications. However, the commercial development of RMBs has been severely hampered by the rapid failure of large-sized Mg metal anodes, especially under fast and deep cycling conditions. Herein, a concept proof involving a large-scale ion-reinforced phytic acid (PA) layer (100 cm × 7.5 cm) with an excellent water-oxygen tolerance, high Mg2+ conductivity, and favorable electrochemical stability is proposed to enable rapid and uniform plating/stripping of Mg metal anode. Guided by even distributions of Mg2+ flux and electric field, the as-prepared large-sized PA-Al@Mg electrode (5.8 cm × 4.5 cm) exhibits no perforation and uniform Mg plating/stripping after cycling. Consequently, an ultralong lifespan (2400 h at 3 mA cm-2 with 1 mAh cm-2) and high current tolerance (300 h at 9 mA cm-2 with 1 mAh cm-2) of the symmetric cell using the PA-Al@Mg anode could be achieved. Notably, the PA-Al@Mg//Mo6S8 full cell demonstrates exceptional stability, operating for 8000 cycles at 5 C with a capacity retention of 99.8%, surpassing that of bare Mg (3000 cycles, 74.7%). Moreover, a large-sized PA-Al@Mg anode successfully contributes to the stable pouch cell (200 and 750 cycles at 0.1 and 1 C), further confirming its significant potential for practical utilization. This work provides valuable theoretical insights and technological support for the practical implementation of RMBs.

Prognostic implication of novel immune-related signature in breast cancer.

Checkpoint inhibitor therapy has become increasingly important and has been endorsed as a treatment regimen in breast cancer. But benefits were limited to a small proportion of patients. We aimed to develop an improved signature on the basis of immune genes for detection of potential benefit from immunotherapy. Gene expression data of patients with breast cancer initially extracted from The Cancer Genome Atlas were analyzed. Ten genes were selected from the interaction of differentially expressed genes as well as immune-related genes to develop a survival signature. We compared the high-risk and low-risk groups by gene set enrichment analysis, immune infiltration, checkpoint molecule expression and immunophenoscore. Ten genes were extracted from interactions of differentially expressed and immune-related genes. The immune risk score was determined on the basis of the Cox regression coefficient of hub genes and validated with the GSE96058 dataset. Immune cell infiltrates, including CD8 + T cells, plasma cells, follicular helper T cells, CD4 + memory T cells, M1 macrophages, regulatory T cells and resting NK cells, were more highly infiltrated in the high-risk group as compared to the low-risk group. Checkpoint molecules, including CTLA-4, PD-L1, TIM-3, VISTA, ICOS, PD-1, and PD-L2, were expressed at markedly lower levels in the high-risk group as compared to the low-risk group. Immunophenoscores, as a surrogate of response to immune checkpoint therapy, was observed significant lower in the high-risk group. The 10-gene prognostic signature could identify patients' survival and was correlated with the biomarkers of immune checkpoint inhibitor therapy, which may guide precise therapeutic decisions in clinical practice.

Catalyzing Desolvation at Cathode-Electrolyte Interface Enabling High-Performance Magnesium-Ion Batteries.

Magnesium ion batteries (MIBs) are expected to be the promising candidates in the post-lithium-ion era with high safety, low cost and almost dendrite-free nature. However, the sluggish diffusion kinetics and strong solvation capability of the strongly polarized Mg2+ are seriously limiting the specific capacity and lifespan of MIBs. In this work, catalytic desolvation is introduced into MIBs for the first time by modifying vanadium pentoxide (V2 O5 ) with molybdenum disulfide quantum dots (MQDs), and it is demonstrated via density function theory (DFT) calculations that MQDs can effectively lower the desolvation energy barrier of Mg2+ , and therefore catalyze the dissociation of Mg2+ -1,2-Dimethoxyethane (Mg2+ -DME) bonds and release free electrolyte cations, finally contributing to a fast diffusion kinetics within the cathode. Meanwhile, the local interlayer expansion can also increase the layer spacing of V2 O5 and speed up the magnesiation/demagnesiation kinetics. Benefiting from the structural configuration, MIBs exhibit superb reversible capacity (≈300 mAh g-1 at 50 mA g-1 ) and unparalleled cycling stability (15 000 cycles at 2 A g-1 with a capacity of ≈70 mAh g-1 ). This approach based on catalytic reactions to regulate the desolvation behavior of the whole interface provides a new idea and reference for the development of high-performance MIBs.

Theoretical insights into the intercalation mechanism of Li, Na, and Mg ions in a metallic BN/VS2 heterostructure.

Layered VS2 has been widely used as a battery anode material owing to its large specific surface area and controllable ion-transport channel. However, its semiconductor properties and poor cycling stability seriously limit its further applications. Herein, a two-dimensional BN/VS2 heterostructure (BVH) was constructed as an anode material for rechargeable metal-ion batteries (RMIBs). Demonstrated using first principles calculations, BVH exhibits a metallic property due to lattice stress between monolayer BN and VS2. BVH displays low ion diffusion energy barriers (0.13, 0.43, and 0.56 eV) and high theoretical capacities (447, 553.5, and 340.7 mA h g-1) for Li+, Na+, and Mg2+ storage. In BVH, the VS2 layer as the main redox center supports charge transfer, while the inactive BN layer enables high structural stability. This synergistic effect is expected to simultaneously achieve a high rate, high capacity, and long life. This design provides an important insight into developing new anode materials for RMIBs.

Organic Molecular Intercalation Enabled Anionic Redox Chemistry with Fast Kinetics for High Performance Magnesium Storage.

Rechargeable magnesium-ion batteries possess desirable characteristics in large-scale energy storage applications. However, severe polarization, sluggish kinetics and structural instability caused by high charge density Mg2+ hinder the development of high-performance cathode materials. Herein, the anionic redox chemistry in VS4 is successfully activated by inducing cations reduction and introducing anionic vacancies via polyacrylonitrile (PAN) intercalation. Increased interlayer spacing and structural vacancies can promote the electrolyte ions migration and accelerate the reaction kinetics. Thanks to this "three birds with one stone" strategy, PAN intercalated VS4 exhibits an outstanding electrochemical performance: high discharge specific capacity of 187.2 mAh g-1 at 200 mA g-1 after stabilization and a long lifespan of 5000 cycles at 2 A g-1 are achieved, outperforming other reported VS4-based materials to date for magnesium storage under the APC electrolyte. Theoretical calculations confirm that the intercalated PAN can indeed induce cations reduction and generate anionic vacancies by promoting electron transfer, which can accelerate the electrochemical reaction kinetics and activate the anionic redox chemistry, thus improving the magnesium storage performance. This approach of organic molecular intercalation represents a promising guideline for electrode material design on the development of advanced multivalent-ion batteries.

Binary Mg-1†at%Gd alloy anode for high-performance rechargeable magnesium batteries.

Rechargeable magnesium batteries (RMBs) become a highly promising candidate for the large-scale energy storage system by right of the high volumetric capacity, intrinsic safety and abundant resources of Mg anode. However, the uneven Mg stripping and large overpotential will cause a severe pitting perforation and the followed failure of Mg anode. Herein, we proposed a high-performance binary Mg-1 at% Gd alloy anode prepared by the melting and hot extrusion. The introduction of 1 at% Gd element can effectively reduce the Mg2+ diffusion energy barrier (0.34 eV) on alloy surface and induces the formation of a robust and low-resistance electrolyte/anode interphase, thus enabling a uniform and fast Mg plating/stripping. As a result, the Mg-1 at.% Gd anode displays a largely enhanced life of 220 h and a low overpotential of 213 mV at a high current density of 5.0 mA cm-2 with 2.5 mAh cm-2 . Moreover, the assembled Mg-1 at.% Gd//Mo6 S8 full cell delivers a high rate performance (73.5 mAh g-1 at 5 C) and ultralong cycling stability of 8000 cycles at 5 C. This work brings new insights to design the new-type and practical Mg alloy anodes for commercial RMBs.

A two-dimensional VO2/VS2 heterostructure as a promising cathode material for rechargeable Mg batteries: a first principles study.

Rechargeable magnesium batteries (RMBs) are considered as highly promising energy storage systems. However, the lack of cathode materials with fast Mg2+ diffusion kinetics and high energy density severely hinders the development of RMBs. Herein, a two-dimensional (2D) VO2/VS2 heterostructure as a RMB cathode material is proposed by introducing an O-V-O layer in VS2 to improve the discharge voltage and specific capacity while keeping the fast Mg2+ diffusion kinetics. Based on first principle calculations, the geometric structures, electronic characteristics of the VO2/VS2 heterostructure, and the adsorption properties and diffusion behaviors of Mg2+ in VO2/VS2 are systematically studied. The metallic properties of VO2/VS2 and a relatively low diffusion barrier of Mg2+ (0.6 eV) in VO2/VS2 enable a large potential in delivering high rate performance in actual RMBs. Compared with traditional VS2 materials (1.25 V), the average discharge platform of VO2/VS2 could be increased to 1.7 V. The theoretical capacities of the layered VS2 and VO2/VS2 are calculated as 233 and 301 mA h g-1, respectively. Thus, the VO2/VS2 heterostructure exhibits a high theoretical energy density of 511.7 W h kg-1, significantly surpassing that of VS2 (291.3 W h kg-1). This work provides important guidance for designing high-energy and high-rate 2D heterostructure cathode materials for RMBs and other multivalent ion batteries.

Enabling Ultrafast Single Mg2+ Insertion Kinetics of Magnesium-Ion Batteries via In Situ Dynamic Catalysis and Re-equilibration Effects.

Magnesium-ion batteries (MIBs) have great potential in large-scale energy storage field with high capacity, excellent safety, and low cost. However, the strong solvation effect of Mg2+ will lead to the formation of solvated ions in electrolytes with larger size and sluggish diffusion/reaction kinetics. Here, the concept of interfacial catalytic bond breaking is first introduced into the cathode design of MIBs by hybriding MoS2 quantum dots with VS4 (VS4@MQDs) as the cathode. The "in situ dynamic catalysis and re-equilibration" effects can catalyze the Cl-Mg bond breaking and trigger single Mg2+ insertion/extraction chemistries, which can significantly accelerate the diffusion and reaction kinetics, as verified by the decreased diffusion energy barriers (0.26 eV for Mg2+ vs 2.47 eV for MgCl+) and fast diffusion coefficient. Benefitting from these dynamic catalysis effects, the constructed VS4@MQD-based MIBs deliver a high discharge capacity of ∼120 mA h g-1 at 200 mA g-1 and a long-term cyclic stability of 1000 cycles at 1 A g-1. The improved performance and detailed characterizations well prove that the active ions in MIBs change from MgCl+/Mg2Cl3+ to Mg2+ with fast kinetics.

Rationally Integrating 2D Confinement and High Sodiophilicity toward SnO2 /Ti3 C2 Tx Composites for High-Performance Sodium-Metal Anodes.

The metallic sodium (Na) is characterized by high theoretical specific capacity, low electrode potential and abundant resources, and its advantages manifests itself as a promising candidate anode of sodium metal batteries (SMBs). However, the vaporization during the plating/stripping or uncontrolled growth of sodium dendrites in sodium metal anodes (SMAs) has posed major challenges to its practical applications. To address this issue, here, the SnO2 /Ti3 C2 Tx composite is rationally fabricated, in which sodiophilic SnO2 nanoparticles are in situ dispersed on the 2D Ti3 C2 Tx , providing the acceptor sites of Na+  that can control vaporization and dendrites. The SnO2 /Ti3 C2 Tx composite anode exhibits smooth and homogeneous morphology after Na-metal deposition cycles, stable Coulombic efficiency (CE) of half cells, long stable cycles of symmetric cells due to highly sodiophilic sites, and confinement effect. In addition, the full cells assembled with Na0.6 MnO2 also show excellent rate performance and cycling performance. These discoveries demonstrate the effectiveness of the acceptor sites and the confinement effect provided by the SnO2 /Ti3 C2 Tx composite, and thus provide an additional degree of freedom for designing SMBs.

Energy Storage Mechanism of C12-3-3 with High-Capacity and High-Rate Performance for Li/Mg Batteries.

The low specific capacity and Mg non-affinity of graphite limit the energy density of ion rechargeable batteries. Here, we first identify that the monolayer C12-3-3 in sp2-sp3 carbon hybridization with high Li/Mg affinity is an appropriate anode material for Li-ion batteries and Mg-ion batteries via the first-principles simulations. The monolayer C12-3-3 can achieve high specific capacities of 1181 mAh/g for Li and 739 mAh/g for Mg, higher than those of most previous anodes. The Li storage reaction is an "adsorption-conversion-intercalation mechanism", while the Mg storage reaction is an "adsorption mechanism". The 2D carbon material of C12-3-3 displays fast diffusion kinetics with low diffusion barriers of 0.41 eV for Li and 0.21 eV for Mg. As a new carbon-based anode material, the monolayer C12-3-3 will promote the practical application of batteries with high-capacity and high-rate performance.

Universal N2O Reaction Gas To Remove Spectral Interferences of Nonmetallic Impurity Elements by Inductively Coupled Plasma Tandem Mass Spectrometry Analysis of High-Purity Magnesium Alloys.

Using N2O as a universal reaction gas, a new strategy was proposed for the highly sensitive interference-free simultaneous determination of nonmetallic impurity elements in high-purity magnesium (Mg) alloys by ICP-MS/MS. In the MS/MS mode, through O-atom and N-atom transfer reactions, 28Si+ and 31P+ were converted to the oxide ions 28Si16O2+ and 31P16O+, respectively, while 32S+ and 35Cl+ were converted to the nitride ions 32S14N+ and 14N35Cl+, respectively. The ion pairs formed via the 28Si+ → 28Si16O2+, 31P+ → 31P16O+, 32S+ → 32S14N+, and 35Cl+ → 14N35Cl+ reactions by the mass shift method could eliminate spectral interferences. Compared with the O2 and H2 reaction modes, the present approach delivered much higher sensitivity and lower limit of detection (LOD) of the analytes. The accuracy of the developed method was evaluated via standard addition method and comparative analysis by sector field ICP-MS (SF-ICP-MS). The study indicates that in the MS/MS mode, use of N2O as reaction gas can provide interference-free conditions and sufficiently low LODs for analytes. The LODs of Si, P, S, and Cl could reach down to 17.2, 4.43, 10.8, and 31.9 ng L-1, respectively, and the recoveries were in the range of 94.0-106%. The determination results of the analytes were consistent with those obtained by SF-ICP-MS. This study presents a systematic method for the precise and accurate quantification of Si, P, S, and Cl in high-purity Mg alloys by ICP-MS/MS. The developed method provides valuable reference that can be expanded and applied to other fields.

Regeneration of Activated Sludge into SiO2-Decorated Heteroatom-Doped Porous Carbon as Advanced Electrodes for Li-S Batteries.

The regeneration of harmful activated sludge into an energy source is an important strategy for municipal sludge treatment and recycling. Herein, SiO2-modified N,S auto-doped porous carbon (NSC@SiO2) with high conductivity (70 S m-1) is successfully obtained through a simple calcination method of the activated sludge from wastewater treatment. Further, P-doped NSC@SiO2 (NSPC@SiO2) is designed to achieve a higher surface area (891 m2 g-1 vs 624 m2 g-1), a larger pore volume (0.87 cm3 g-1 vs 0.08 cm3 g-1), and more carbon defects. Due to its special structure, NSPC@SiO2 is used as a sulfur host of lithium-sulfur batteries. The results of polysulfide adsorption experiments, S 2p X-ray photoelectron spectra (XPS), Li2S nucleation experiments, polysulfide symmetric cells, measurement of the galvanostatic intermittent titration (GITT), polarization voltage difference, lithium-ion diffusion rate, and Tafel slope verified that NSPC@SiO2 greatly improved the adsorption capacity of polysulfides, lowered the barrier to Li2S formation and the internal resistances of cells, and accelerated Li+ ion diffusion and the reaction kinetics of polysulfide conversion, resulting in the excellent performance of polysulfide capture and superior rate performance and cyclic stability. By comparing NSPC@SiO2 with NSC@SiO2, a higher initial capacity (1377 mAh g-1 vs 1150 mAh g-1 at 0.1C), better rate capacity (912 mAh g-1 vs 719 mAh g-1 at 2C), and low capacity decay (0.094% per cycle within 200 cycles) are obtained. Our work provides direction for the treatment, disposal, and resource utilization of activated sludge.

Unusual Spreading of Strain Neutral Layer in AZ31 Magnesium Alloy Sheet during Bending.

In this work, we reported an unusual phenomenon of strain neutral layer (SNL) spreading in an as-rolled AZ31B magnesium alloy sheet during V-bending. The SNL on the middle symmetrical surface perpendicular to the transverse direction (TD) of the sheet extended to the compression region and was accompanied by a mound-like feature. However, the SNL on the side surface perpendicular to the TD was distributed with a parallel band feature. The underlying mechanism was revealed by the finite element (FE) analysis. The results indicate that the three-dimensional compressive stresses in the compression region of the bending samples were responsible for the above phenomenon. Moreover, the area of the SNL in the middle position gradually decreased as the bending test progressed. The findings in this study provide some new insights into the bending deformation behavior of magnesium alloy.

Review: Degradable Magnesium Corrosion Control for Implant Applications.

Magnesium (Mg) alloys have received increasing interest in the past two decades as biomaterials due to their excellent biological compatibility. However, the corrosion resistance of Mg alloys is relativity low which limits their usage in degradable implant applications, and controlling the corrosion resistance is the key to solving this problem. This review discusses the relative corrosion mechanisms, including pitting, filiform, high temperature, stress corrosion, etc., of Mg alloys. Various approaches like purification (Fe, Ni, Cu, etc.), micro-alloying (adding Zn, Mn, Ca, RE elements, and so on), grain refinement (severe plastic deformation, SPD, etc.), and surface modifications (various coating methods) to control corrosion and biological performance are summarized. Moreover, the in vivo implantations of Mg alloy vascular stents and the issues that have emerged based on the reports in recent years are introduced. It is recommended that corrosion mechanisms should be further investigated as there is no method that can remove all the impurities and a new purification approach needs to be developed. The concentration of micro-alloy elements should be carefully controlled to avoid superfluous compounds. Developing new continuous SPD methods to achieve fine-grained Mg alloys with a large size scale is necessary. The development of a multifunctional coating could also be considered in controlling the Mg degradation rate. Moreover, the research trends and challenges in the future of Mg biomaterials are proposed.

Switchable and Strain-Releasable Mg-Ion Diffusion Nanohighway Enables High-Capacity and Long-Life Pyrovanadate Cathode.

Rechargeable magnesium batteries (RMBs) suffer from low capacity and poor cyclability of cathode materials, which is due to the sluggish Mg2+ diffusion kinetics and large lattice strain. Here, a layer-interweaving mechanism in lamellar cathode to simultaneously facilitate Mg2+ diffusion and release Mg2+ -insertion strain is reported. In the Cu3 V2 O7 (OH)2 ·2H2 O (CVOH) cathode, Mg2+ diffusion highways are generated by the vertical interweaving of CVOH layers and V6 O13 layers that nucleate in CVOH during discharging, which are switchable by Mg2+ insertion/extraction. These highways enhance the Mg2+ diffusion coefficient by three orders of magnitude and release 50% Mg2+ -insertion strain. This enables CVOH to exhibit a high capacity of 262 mAh g-1 at high current density of 250 mA g-1 in aqua, and extremely low capacity loss of 0.0004% per cycle in the activated carbon//CVOH cell. This work inspires designing the magnesiation phase transformation of electrodes to resolve both kinetic and strain issues for high-performance RMBs.

A Predictive Model for Nonsentinel Node Status after Sentinel Lymph Node Biopsy in Sentinel Lymph Node-Positive Chinese Women with Early Breast Cancer.

BACKGROUND: Axial lymph node dissection (ALND) is needed in patients with positive sentinel lymph node (SLN). ALND is easy to cause upper limb edema. Therefore, accurate prediction of nonsentinel lymph nodes (non-SLN) which may not need ALND can avoid excessive dissection and reduce complications. We constructed a new prognostic model to predict the non-SLN metastasis of Chinese breast cancer patients. METHODS: We enrolled 736 patients who underwent sentinel lymph node biopsy (SLNB); 228 (30.98%) were diagnosed with SLNB metastasis which was determined by intraoperative pathological detection and further accepted ALND. We constructed a prediction model by univariate analysis, multivariate analysis, "R" language, and binary logistic regression in the abovementioned 228 patients and verified this prediction model in 60 patients. RESULTS: Based on univariate analysis using α = 0.05 as the significance level for type I error, we found that age (P=0.045), tumor size (P=0.006), multifocality (P=0.011), lymphovascular invasion (P=0.003), positive SLN number (P=0.009), and negative SLN number (P=0.034) were statistically significant. Age was excluded in multivariate analysis, and we constructed a predictive equation to assess the risk of non-SLN metastasis: Logit(P)=Ln(P/1 - P)=0.267∗a+1.443∗b+1.078∗c+0.471∗d - 0.618∗e - 2.541 (where "a" represents tumor size, "b" represents multifocality, "c" represents lymphovascular invasion, "d" represents the number of metastasis of SLN, and "e" represents the number of SLNs without metastasis). AUCs for the training group and validation group were 0.715 and 0.744, respectively. When setting the risk value below 22.3%, as per the prediction equation's low-risk interval, our model predicted that about 4% of patients could avoid ALND. CONCLUSIONS: This study established a model which demonstrated good prognostic performance in assessing the risk of non-SLN metastasis in Chinese patients with positive SLNs.