3D Hierarchically Assembled Porous Wrinkled-Paper-like Structure of ZnCo₂O₄ and Co-ZnO@C as Anode Materials for Lithium-Ion Batteries

Abstract

Three dimensional (3D) hierarchically assembled porous transition metal oxide nanostructures are promising materials for next generation rechargeable Li-ion batteries (LIBs). Here, the controlled synthesis of 3D hierarchically porous ZnCo2O4 “wrinkled-paper-like” structure constructed from two-dimensional (2D) nanosheets (∼20 nm thick) through calcination of corresponding mixed metal carbonate intermediate is presented. The mixed metal hydroxy-carbonate intermediate with wrinkled-paper-like structure has been synthesized by a novel organic surfactant and organic solvent free protocol at reflux condition using an aqueous solution of corresponding metal salt and ammonium carbonate. Active-inactive nanocomposites of Co-ZnO@C with similar wrinkled-paper-like morphology with varying carbon content, have also been synthesized through carbonation of hydroxyl-carbonate intermediate followed by calcination (under reducing environment). Calcination of the carbon coated mixed metal carbonate results in phase separated uniform Co metal and ZnO particles embedded on carbon matrix. The results demonstrate that incorporation of ∼23% carbon in the matrix significantly improves the performance as anode material in LIB by exhibiting high specific capacity and enhanced cycling performance. At a current density of 100 mAg–1, it shows an excellent initial specific capacity of 527 mAhg–1, which is maintained up to 50 cycles. In fact, a slight gradual increase in capacity with cycling has been observed.

Reversible Lithium Storage in Manganese 1,3,5-Benzenetricarboxylate Metal–Organic Framework with High Capacity and Rate Performance

“…On the other hand, the mesoporous walls would increase the active surface area and provide low resistance pathways for the ions. 24,25 The BET adsorption isotherm (Figure 4a) is convex in nature up to P/P 0 = 1.0, and a typical type-III isotherm with a discrete hysteresis loop starting from P/P 0 ≈ 0.5 reveals a mixed H3 and H1 type indicating presence of interparticle as well as structural pores. The corresponding pore size distribution was calculated by Barrett− Joyner−Halenda (BJH) method using the desorption part (Figure 4b).…”

Two-dimensional ultrathin ZnCo2O4 nanosheets: general formation and lithium storage application

“…26 Giri et al synthesized wrinkled-paper-like ZnCo 2 O 4 with reasonably good performance for lithium storage. 27 Zhou et al presented highly symmetric Zn x Co 3Àx O 4 hollow polyhedra with a high reversible capacity of 990 mA h g À1 upon 50 charge-discharge cycles. 28 However, the long-term cycling stability and high-rate performance of the present ZnCo 2 O 4 anodes are still unsatisfactory.…”

Anodic ZnO-Graphene Composite Materials in Lithium Batteries

“…ZnO is a material with great versatility, in terms of synthesis methods and nanostructures, such as nanobars [20], nanosheets [25,26], 3D nanostructures [27,28], and nanocrystals [18,29]. Within the synthesis methods, relatively complex methods are found such as the chemical vapor deposition (CVD) [30], Vapor Phase Transport (VPT) [31] for its acronym in English.…”

“…Within the synthesis methods, relatively complex methods are found such as the chemical vapor deposition (CVD) [30], Vapor Phase Transport (VPT) [31] for its acronym in English. These techniques are relatively expensive and complex, compared to others such as chemical precipitation [28,32], sol-gel [23,[33][34][35], hydrothermal [29,[36][37][38][39][40][41], or solvothermal [19,42,43].…”

“…Several authors such as Kundu et al [20] and Liu et al [48] obtained from chemical precipitation at normal conditions nanobars and ZnO nanoparticles, respectively. According to these same authors, they obtained the nanoparticles or nanobars individually or separately, and in the case of Lui et al [48], they performed an extra process of carbon coating or as Giri et al [28] who performed a hydrothermal procedure to coat the nanoparticles. On the other hand, Ramadoss et al [32] obtained an CM where they precipitated nanoparticles of ZnO in situ, on graphene sheets.…”