硅酸盐学报2025，Vol.53Issue(4)：785-791,7.DOI:10.14062/j.issn.0454-5648.20250004
高负载稳定循环钠离子电池微米锡电极材料
High Mass Loading and Stable Cycling Micrometer Tin Electrode Material for Sodium-Ion Batteries
摘要
Abstract
Introduction High-capacity anode materials are essential for high-energy sodium-ion batteries.Sn anodes with their high theoretical capacity can face significant volume expansion(i.e.,up to 420％)during sodiation,thus affecting material stability.Previous strategies for long-cycling micron-sized Sn are low loadings and inadequate for commercial needs.Enhancing cyclic stability under a high mass loading is thus crucial for high-performance sodium-ion batteries.In this paper,we simply mixed Sn with HC to form an HC"fence"that could prevent Sn particle reagglomeration and allow self-evolution.Adding 50％(in mass)HC boosted Sn/HC cyclic stability without shedding or cracking after 100 cycles at 70％(in mass)HC.The optimized μSn30HC70 delivered 1.8 mA·h/cm2 at 200 mA/g and retained 93.3％capacity after 200 cycles at 500 mA/g.The μSn30HC70‖Na3V2(PO4)3(NVP)full cell had 186 W·h/kg energy density at 0.5 C and retained 92.11％capacity at 6 C. Methods A slurry was prepared via mixing Sn/HC,conductive agent(SP),and sodium alginate(SA)in deionized water in a mass ratio of 8∶1∶1.The mixture was coated onto carbon-coated aluminum foil,dried under vacuum at 80 ℃ for 12 h,and then cut into electrode disks with the diameter of 11 mm.The electrode disks with different μSnxμHC(100-x)ratios were obtained,i.e.,HC,μSn20HC80,μSn30HC70,μSn40HC60,and μSn50HC50,via adjusting Sn content in the mixed anode(x=0％,20％,30％,40％,and 50％).In an argon-filled glovebox(the volume fractio of H2O,O2 ≤ 1 × 10-6),2325-type coin-cell half-cells were assembled with sodium as a counter/reference electrode,Celgard2500 as a separator,and 1 mol/L NaPF6 in Bis(2-methoxy ethyl)ether as an electrolyte.The full cells of(μSn30HC70‖NVP and μSn‖NVP)were also constructed with μSn30HC70/μSn as an anode and NVP as a cathode.The calculations of capacity and energy density excluded the masses of binder and conductive agent. Results and discussion At a loading of 5.5 mg/cm2,μSn experiences a rapid capacity decay,losing up to 60％after 200 cycles.However,blending 50％(in mass)HC enhances Sn/HC cyclic stability under the same conditions.The SEM images of the sample after 100 cycles show the best-preserved electrode surface morphology with 70％(in mass)of HC,absent of active material shedding or surface cracking.This indicates that 70％(in mass)of HC achieves a structural stability for Sn anode,exhibiting a promising potential for developing long-term cyclic stability.At a current density of 500 mA/g,this electrode retains 93.3％of its initial capacity after 200 cycles. The results show that the capacity contribution of HC within the electrode material increases as the HC content increases,via comparing the voltage-capacity profiles of Sn/HC anodes with different HC proportions.The charging platforms of Sn at 0.2 V and 0.31 V merge into a platform,potentially due to the reduced transport resistance facilitated by HC.This can be further clarified via comparing the electrochemical impedance spectroscopy(EIS)data of μSn30HC70 and pure Sn,where the intrinsic impedance and diffusion impedance of Sn/HC both are lower than those of pure Sn. The ex-situ X-ray Diffraction(XRD)patterns indicate the phase transitions of Sn/HC at different potentials.A peak at 2θ of 35.7° appears and disappears during the charge-discharge process,indicating the high reversibility of Sn material during cycling. The μSn30HC70‖NVP full cell validates Sn/HC practicality in sodium-ion batteries.achieving 186 W·h/kg energy density at 0.5 C and retains 92.11％at 6 C Conclusions Mixing HC with Sn effectively could enhance the cyclic stability of micron-sized Sn.This was attributed to the HC fence structure around Sn particles.The optimized μSn30HC70 anode had an areal capacity of 1.8m·h/cm2 at a current density of 200 mA/g and retained 93.3％after 200 cycles at a current density of 500mA/g.The full cell assembled with NVP maintained a capacity retention of 92.11％after 100 cycles at 0.5 C,further validating the effectiveness of the HC"fence"structure design in improving the stability of Sn anodes under high-mass loading conditions.关键词
微米锡/钠离子电池/高负载量/循环稳定性Key words
micrometer-sized tin/sodium-ion battery/high-loading/cycle stability分类
信息技术与安全科学引用本文复制引用
王钦,张艳岗,梁君飞,王华..高负载稳定循环钠离子电池微米锡电极材料[J].硅酸盐学报,2025,53(4):785-791,7.基金项目
山西省科技成果转化引导专项(202304021301032) （202304021301032）
山西省基础研究计划(202403021211075). （202403021211075）
