基于海藻酸钠交联的NiO/C复合材料制备及其储锂性能

NiO作为过渡金属氧化物代表,具有能量密度较高、成本低的优点,在锂离子电池负极材料的应用中引起了广泛关注。通过海藻酸钠与金属离子的自主交联反应,以及碳化、氧化过程,制备了低成本的多孔纳米NiO/C复合材料。得到的复合材料中,NiO纳米颗粒分散均匀且被石墨化碳层包覆,并嵌入多孔相互连通的碳基体中,在提升复合材料整体导电性的同时抑制了活性材料在电化学反应中的体积膨胀。将其用作锂离子电池负极材料时,NiO/C复合材料在0.1,1 A/g的电流密度下分别具有608.2,307.2 mAh/g的比容量,并且在0.1 A/g电流密度下经过100圈循环后仍保持448 mAh/g的比容量,显示出优良的循环稳定性。优良的电化学性能充分显示出NiO/C复合材料在锂离子电池负极材料中的应用潜能。

Self-Cross-Link Synthesis of Porous Nanoscale NiO/C Composites Electrode Materials for Lithium Storage

As a representative of transition metal oxides,NiO has the advantages of high energy density and low cost,and thus has attracted extensive attention in the application of lithium-ion batteries anode materials.Porous nanoscale NiO/C composites with low cost are prepared by a simple self-cross-link reaction of sodium alginate with metal ions and following carbonation and oxidation process.In the resultant composites,NiO nanoparticles coated by graphitic layers are uniformly embedded into porous carbon frameworks.The porous carbon frameworks not only enhance the electrical conductivity,but also inhibit the volume expansion of NiO nanoparticles during electrochemical reactions.Applying these in the anodes of lithium-ion batteries,these structural features enable the NiO/C composites to deliver high specific capacity of 608.2 and 307.2 mAh/g at the current density of 0.1 and 1 A/g,respectively,and the composites still maintain the specific capacity of 448 mAh/g after 100 cycles under the current density of 0.1 A/g,showing such excellent cycle stability.Such well electrochemical performance demonstrates the potential of NiO/C composites in anodes for lithium-ion batteries.