Ni-Composite Microencapsulated Graphite as the Negative Electrode in Lithium-Ion Batteries I. Initial Irreversible Capacity Study
نویسندگان
چکیده
A novel approach for suppressing the solvated lithium intercalation in graphite was developed by microencapsulating graphite with nanosized Ni-composite particles. The Ni-composite graphite showed great improvement in charge-discharge performance, coulomb efficiency, and cycling behavior when used as the negative electrode in a Li-ion cell with propylene carbonate (PC)-based electrolyte. For example, a 10 wt % Ni-composite coating increased the initial charge-discharge coulomb efficiency of SFG75 graphite (75 mm, Timcal America) from 59 to 84% and the reversible capacity by 30-40 mAh/g. The Ni-composite coating consisted of nanosized particles distributed over the surface of the graphite particle, which effectively blocked some of the edge surfaces exposed to the electrolyte. This minimized solvated lithium intercalation at these edge sites, which subsequently minimized the PC reduction within the graphite and the exfoliation of the graphene layers, and also gas evolution. Corresponding improvements in both the charge-discharge performance and safety of the negative electrode in a rechargeable Li-ion cell resulted. © 2000 The Electrochemical Society. S0013-4651(99)08-113-6. All rights reserved.
منابع مشابه
Ni-Composite Microencapsulated Graphite as the Negative Electrode in Lithium-Ion Batteries II. Electrochemical Impedance and Self-Discharge Studies
Electrochemical impedance and self-discharge studies were carried out to investigate lithium intercalation into bare and Ni-coated KS10 graphite. Values of the charge-transfer resistances, exchange current densities, surface film resistances, and lithium-ion diffusion coefficients as functions of the state of charge (SOC) all favored the 10 wt % Ni composite KS10 graphite over bare KS10 graphit...
متن کاملStudy of polypyrrole graphite composite as anode material for secondary lithium-ion batteries
Pyrrole was polymerized onto commercial SFG10 graphite by in situ polymerization technique. Polymerization decreases the initial irreversible capacity loss of the graphite anode. The decrease in the irreversible capacity loss is due to the reduction in the thickness of the solid electrolyte interface (SEI) layer formed. PPy/C (7.8%) gives the optimum performance based on the irreversible capaci...
متن کاملPalladium-microencapsulated graphite as the negative electrode in Li-ion cells
A Pd-encapsulated graphite electrode was used as the negative electrode in Li-ion cells. Through dispersion of ultrafine nanoparticles of palladium on the surface of graphite, the interfacial properties of the carbon surface were modified. The presence of the palladium Ž . dramatically reduces the initial irreversible capacity of the graphite in propylene carbonate PC -based electrolyte. Pallad...
متن کاملInitial Discharge Capacity of Manganese Cobaltite as Anode Material for Lithium Ion Batteries
Nanostructured manganese cobalt oxide spinel (MnCo2O4) are prepared by co-precipitation method and calcined at 650 and 750°C. Morphological studies show that by increasing the calcination temperature from 650 to 750°C, morphology of the particles changes from quasi-plate to polyhedral. The MnCo2O4 calcined at 650°C could deliver an initial discharge capacity of 1438 mAh g-1 under current densit...
متن کاملRecent Progress in Design of Biomass-Derived Hard Carbons for Sodium Ion Batteries
Sodium ion batteries (SIBs) have attracted lots of attention over last few years due to the abundance and wide availability of sodium resources, making SIBs the most cost-effective alternative to the currently used lithium ion batteries (LIBs). Many efforts are underway to find effective anodes for SIBs since the commercial anode for LIBs, graphite, has shown very limited capacity for SIBs. Amo...
متن کامل