Fabrication of binder-free SnO2 nanoparticle electrode for lithium secondary batteries by electrophoretic deposition method

Antimony doped SnO2nanowire@C core-shell structure as a high-performance anode material for lithium-ion battery

SnO₂is considered as one of the high specific capacity anode materials for Lithium-ion batteries. However, the low electrical conductivity of SnO₂limits its applications. This manuscript reports a simple and efficient approach for the synthesis of Sb-doped SnO₂nanowires (NWs) core and carbon shell structure which effectively enhances the electrical conductivity and electrochemical performance of SnO₂nanostructures. Sb doping was performed during the vapor-liquid-solid synthesis of SnO₂NWs in a horizontal furnace. Subsequently, carbon nanolayer was coated on the NWs using the DC Plasma Enhanced Chemical Vapor Deposition approach. The carbon-coated shell improves the Solid-Electrolyte Interphase stability and alleviates the volume expansion of the anode electrode during charging and discharging. The Sb-doped SnO₂core carbon shell anode showed the superior specific capacity of 585 mAhg^-1after 100 cycles at the current density of 100 mA g^-1, compared to the pure SnO₂NWs electrode. The cycle stability evaluation revealed that the discharge capacity of pure SnO₂NWs and Sb doped SnO₂NWs electrodes were dropped to 52 and 152 mAh g^-1after100th cycles. The process of Sb doping and carbon nano shielding of SnO₂nanostructures is proposed for noticeable improvement of the anode performance for SnO₂based materials.

Direct Electrophoretic Deposition of Binder-Free Co3O4/Graphene Sandwich-Like Hybrid Electrode as Remarkable Lithium Ion Battery Anode

Co₃O₄ is emerging as a promising anode candidate for lithium ion batteries (LIBs) with high theoretical capacity (890 mAh g^-1) but suffers from poor electrochemical cycling stability resulting from the inferior intrinsic electronic conductivity and large volume changes during electrochemical cycling. Here, a new electrophoretic deposition Co₃O₄/graphene (EPD Co₃O₄/G) hybrid electrode is developed to improve the electrochemical performance. Through EPD, Co₃O₄ nanocubes can be homogeneously embedded between graphene sheets to form a sandwich-like structure. Owing to the excellent flexibility of graphene and a large number of voids in this sandwich-like structure, the structural integrity and unobstructed conductive network can be maintained during cycling. Moreover, the electrode kinetics has proved to be a fast surface-controlled lithium storage process. As a result, the Co₃O₄/G hybrid electrode exhibits high specific capacity and excellent electrochemical cycling performance. The Co₃O₄/G hybrid electrode was also further studied by in situ electrochemical XRD to understand the relationship of its structure and performance: (1) The observed Li_xCo₃O₄ indicates an intermediate of possible small volume change in the first discharging. (2) The theoretical capacity achievement of the Co₃O₄ in hybrid electrode was evidenced. (3) The correlation between the electrochemical performance and the structural evolution of the Co₃O₄/G hybrid electrode was discussed detailedly.

Binder-free Si nanoparticle electrode with 3D porous structure prepared by electrophoretic deposition for lithium-ion batteries

A binder-free silicon (Si) based electrode for lithium-ion battery was fabricated in an organic solvent through one-step electrophoretic deposition (EPD). The nanosized Si and acetylene black (AB) particles were bonded tightly together to form a homogeneous co-deposited film with 3D porous structure through the EPD process. The 3D porous structure provides buffer spaces to alleviate the mechanical stress due to silicon volume change during the cycling and improves lithium-ion conductivity by shortening ion diffusion length and better ion conducting pathway. The electrode prepared with 5 s deposition duration shows the best cycling performance among electrodes fabricated by EPD method, and thus, it was selected to be compared with the silicon electrode prepared by the conventional method. Our results demonstrate that the Si nanoparticle electrode prepared through EPD exhibits smaller cycling capacity decay rate and better rate capability than the electrode prepared by the conventional method.

Enhanced charge–discharge properties of SnO2 nanocrystallites in confined carbon nanospace

The reversibility of SnO₂–Sn conversion and Sn–Li alloying/de-alloying reactions was greatly enhanced by the confinement of SnO₂ nanocrystallites in regulated carbon nanospace.