One-step synthesis of Co-doped Zn₂SnO₄–graphene–carbon nanocomposites with improved lithium storage performances

Abstract

Co-doped Zn 2 SnO 4 -graphene-carbon nanocomposites have been prepared for the first time through a convenient one-step hydrothermal method. The size of Co-doped Zn 2 SnO 4 nanoparticles is about 3-5 nm and they are well dispersed on graphene nanosheets and carbon layer. L-Ascorbic acid is introduced to serve as a reductant for GO and carbon sources. The doping of Co can enhance the crystalline degree of Zn 2 SnO 4 nanoparticles. When evaluated as anode materials for lithium ion batteries, the Co-ZTO-G-C nanocomposites exhibited a significantly higher reversible capacity of 699 mA h g À1 after 50 cycles at 100 mA g À1 and an improved cycling stability of 461 mA h g À1 after 200 cycles at 500 mA g À1 compared with Co-ZTO-G and ZTO-G-C nanocomposites. Moreover, even at a high current density of 1000 mA g À1 , the reversible capacity of 418 mA h g À1 still remained. The improved electrochemical performance can be attributed to the synergy of the graphene substrate, the protective carbon layer, the uniform ultrafine Zn 2 SnO 4 nanoparticles and Co doping. Therefore, Co-ZTO-G-C nanocomposites show great prospect as anodes for lithium-ion batteries.

Three-dimensional Mn-doped Zn2GeO4 nanosheet array hierarchical nanostructures anchored on porous Ni foam as binder-free and carbon-free lithium-ion battery anodes with enhanced electrochemical performance

“…In particular, cationic doping has been considered as another effective strategy to improve electrical conductivity and charge transfer ability and thus enhance the electrochemical performance of metal oxide anode materials. [31][32][33][34][35][36] Until now, different metal cations have been incorporated into the lattice of a variety of metal oxides to improve the electrochemical performance. For instance, Cu cation doping can increase the specic capacity from 361 mA h g À1 of Mn 2 O 3 to 642 mA h g À1 of Cu-doped Mn 2 O 3 .…”

“…34 Recently, it has been reported that Co doping in Zn 2 SnO 4 can greatly enhance the cycle stability and rate capability. 35 On the other hand, most of the conventional LIB anodes usually use polymers and carbon black as binders, which may experience virtual swelling in commonly used electrolytes, leading to a rapid capacity degradation, poor cycle stability and rate capability. 31 The polymer and carbon black additives generate a weight increase (10-40%) in battery electrodes and extra steps to mix and combine those materials into a lm form.…”

In situ synthesis of hierarchical CoFe2O4 nanoclusters/graphene aerogels and their high performance for lithium-ion batteries

“…23 To date, intensive efforts have been devoted to preparing graphene-based transition metal oxide composites, which exhibit great improvements in their electrochemical performance of high lithium storage capability. [24][25][26][27] Compared with two-dimensional (2D) graphene, three-dimensional (3D) graphene aerogels (GAs) have attracted considerably more attention due to their unique 3D interconnected framework, high surface area, fast mass and electron transport rate and good flexibility. 28 Therefore, it is still desirable to develop a simple method to achieve 3D hierarchical CoFe 2 O 4 /GAs composites with a longer cycling life and higher rate performance.…”

Zn2GeO4 and Zn2SnO4 nanowires for high-capacity lithium- and sodium-ion batteries

“…A number of research groups also suggested the partial contribution of these reactions. 30,34,[36][37][38] Our value is less than the theoretical capacity (1231 mA h g -1 ) of mechanism "B". The remaining portion of the crystalline α-and β-Sn phase could be evidence for an incomplete alloying reaction.…”