Hongying Hou

Durability of sulfonated aromatic polymers for proton-exchange-membrane fuel cells.

As a key component of proton-exchange-membrane fuel cells (PEMFCs), proton-exchange membranes (PEMs) must continuously withstand very harsh environments during long-term fuel cell operations. With the coming commercialization of PEMFCs, investigations into the durability and degradation of PEMs are becoming more and more urgent and interesting. Herein, various recent attempts and achievements to improve the durability of sulfonated aromatic polymers (SAPs) are reviewed and some further developments are predicted. Extensive investigations into inexpensive SAPs as alternative electrolyte membranes include modification of available polymer materials; design, synthesis, and optimization of new macromolecules; durability testing; and exploring the degradation mechanisms.

In situ Ti3+-doped TiO2 nanotubes anode for lithium ion battery

In order to improve the electrical conductivity and electrochemical performances, three-dimensional oriented noncrystalline TiO2 nanotube arrays (TiO2NT) were modified with Ti3+ via one-step in situ electrochemical self-doping. The as-synthesized Ti3+-doped TiO2NT (Ti3+/TiO2NT) electrode was investigated in terms of XPS, SEM, EDX, galvanostatic charge/discharge, cycle stability, rate performance, cyclic voltammetry (CV) and AC impedance. As expected, Ti3+/TiO2NT electrode displayed higher discharge capacity, rate performance, cycle stability and Li+ diffusion coefficient than the bare one, possibly due to improved electrical conductivity.

Binder-free combination of graphene nanosheets with TiO2 nanotube arrays for lithium ion battery anode

Binder-free combination of graphene nanosheets with oriented TiO2 nanotube arrays was designed and achieved via one-step facile electrodeposition. The structure and morphology of as-prepared composite graphene nanosheets/TiO2 nanotube arrays were studied in terms of SEM, FESEM, EDX, TEM, Raman and FTIR. Furthermore, the corresponding electrochemical performances were evaluated in terms of galvanostatic charge/discharge, cycle stability and AC impedance. As expected, the composite graphene nanosheets/TiO2 nanotube arrays displayed higher discharge capacity, cycle stability and Li+ diffusion coefficient than bare TiO2 nanotube arrays. High Li-storage activity, superior conductivity and large surface area of graphene nanosheets should be responsible for improved electrochemical performances.

Binder-free integration of insoluble cubic CuCl nanoparticles with a homologous Cu substrate for lithium ion batteries

Binder-free integration of a novel insoluble cubic cuprous chloride (CuCl) nanoparticle anode material with homologous Cu foil was designed and achieved via facile in situ electrochemical self-assembly for the first time. The integrated CuCl/Cu electrode for lithium ion batteries was studied in terms of SEM, EDX, XRD, galvanostatic charge/discharge, cycle stability, rate performance, cyclic voltammograms (CV) and AC impedance. As expected, insoluble cubic CuCl nanoparticles did in situ grow and tightly combine with the surface of Cu foil, and the resultant CuCl/Cu electrode delivered a reversible discharge capacity of 250.6 mA h g−1 after 300 cycles at 2C, indicating satisfactory cyclic stability. In addition, the corresponding Li+ diffusion coefficient was calculated to be 1.8 × 10−11 cm2 s−1, higher than that of the MnO anode material in literature. Binder-free integration of homologous materials via self-assembly can not only ensure the tight combination of insoluble CuCl nanoparticles with Cu foil, but also avoid negative effects due to the polymer binder on electrochemical performance.

Sulfonated graphene oxide with improved ionic performances

Graphene oxide is well known as a new kind of functional materials because of its super-high specie surface area, mechanical strength, as well as excellent amphipathicity. In this article, graphene oxide was further sulfonated via substitution reaction with diazo salt of sulfanilic in order to endow graphene oxide with better ion exchange capacity and proton conductivity. The microstructure and morphology of the obtained sulfonated graphene oxide were characterized by X-ray diffraction (XRD), Raman spectra, and TEM, while the sulfonation of graphene oxide was confirmed by energy-dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR) spectra. As expected, ion exchange capacity and proton conductivity of sulfonated graphene oxide increased by about 0.589 and 33.6 times than those of graphene oxide, respectively.

Recycled tetrahedron-like CuCl from waste Cu scraps for lithium ion battery anode

The wide applications of metal Cu inevitably resulted in a large quantity of waste Cu materials. In order to recover the useful Cu under the mild conditions and reduce the environmental emission, waste Cu scraps were recycled in the form of CuCl powders with high economic value added (EVA) via the facile hydrothermal route. The recycled CuCl powders were characterized in terms of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results suggested that the recycled CuCl powders consisted of many regular tetrahedron-like micro-particles. Furthermore, in order to reduce the cost of lithium ion battery (LIB) anode and build the connection of waste Cu scraps and LIB, the recycled CuCl powders were evaluated as the anode active material of LIB. As expected, the reversible discharge capacity was about 171.8mAh/g at 2.0C even after 50 cycles, implying the satisfactory cycle stability. Clearly, the satisfactory results may open a new avenue to develop the circular economy and the sustainable energy industry, which would be very important in terms of both the resource recovery and the environmental protection.

Stabilized sulfonated aromatic polymers by in situ solvothermal cross-linking

The cross-link reaction via sulfone bridges of sulfonated polyetheretherketone (SPEEK) by thermal treatment at 180 °C in presence of dimethylsulfoxide (DMSO) is discussed. The modifications of properties subsequent to the cross-linking are presented. The mechanical strength as well as the hydrolytic stability increased with the thermal treatment time, i.e., with the degree of cross-linking. The proton conductivity was determined as function of temperature, IEC, degree of cross-linking and hydration number. The memory effect, which is the membrane ability to “remember” the water uptake reached at high temperature also at lower temperature, is exploited in order to achieve high values of conductivity. Membranes swelled at 110 °C can reach a conductivity of 0.14 S/cm at 80°C with a hydration number () of 73.

Recycled hierarchical tripod-like CuCl from Cu-PCB waste etchant for lithium ion battery anode.

Hierarchical CuCl with high economic value added (EVA) was successfully recycled with 85% recovery from the acid Cu printed circuit board (Cu-PCB) waste etchant via facile liquid chemical reduction. The micro-structure and morphology of the recycled hierarchical CuCl were systematically characterized in terms of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET). Furthermore, the corresponding electrochemical performances as lithium ion battery (LIB) anode were also investigated in terms of galvanostatic charge/discharge, cyclic voltammetry (CV) and AC impedance. As expected, the recycled CuCl displayed a hierarchical tripod-like structure and large specific surface area of 21.2m2/g. As the anode in LIB, the reversible discharge capacity was about 201.4 mAh/g even after 100 cycles, implying the satisfactory cycle performance. Clearly, the satisfactory results may open a new avenue to develop the sustainable industry, which is very important in terms of both the resource recovery and the environmental protection.

Binder-free combination of amorphous TiO2 nanotube arrays with highly conductive Cu bridges for lithium ion battery anode

Binder-free combination of highly conductive Cu bridges with amorphous TiO2 nanotube arrays for lithium ion battery anode were designed and achieved via one-step facile electrodeposition. The obtained composite Cu/TiO2 nanotubes electrode was studied in terms of XRD, SEM, EDX, galvanostatic charge/discharge, cycle stability, rate performance, and AC impedance. As expected, the composite electrode delivered higher discharge capacity, rate performance, and cycle stability than the bare one, possibly due to improved electrical conductivity and the synergy effect between conductive Cu bridges and amorphous TiO2 nanotube arrays.

Reutilization of the expired tetracycline for lithium ion battery anode.

Waste antibiotics into the natural environment are the large challenges to the environmental protection and the human health, and the unreasonable disposal of the expired antibiotics is a major pollution source. Herein, to achieve the innocent treatment and the resource recovery, the expired tetracycline was tried to be reutilized as the electrode active material in lithium ion battery (LIB) for the first time. The micro-structure and element component of the expired tetracycline were characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Furthermore, the corresponding electrochemical performances were also investigated by galvanostatic charge/discharge and cyclic voltammetry (CV). To be satisfactory, the expired-tetracycline-based electrode delivered the initial specific discharge capacity of 371.6mAh/g and the reversible specific capacity of 304.1mAh/g after 200cycles. The decent results will not only offer an effective strategy to recycle the expired tetracycline, but also shed a new light on the cyclic economy and the sustainable development.