Muhammad-Sadeeq Balogun

Oxygen‐Deficient Hematite Nanorods as High‐Performance and Novel Negative Electrodes for Flexible Asymmetric Supercapacitors

Oxygen-deficient α-Fe2 O3 nanorods with outstanding capacitive performance are developed and demonstrated as novel negative electrodes for flexible asymmetric supercapacitors. The asymmetric-supercapacitor device based on the oxygen-deficient α-Fe2 O3 nanorod negative electrode and a MnO2 positive electrode achieves a maximum energy density of 0.41 mW·h/cm(3) ; it is also capable of charging a mobile phone and powering a light-emitting diode indicator.

Recent advances in metal nitrides as high-performance electrode materials for energy storage devices

Energy storage devices are the key components for successful and sustainable energy systems. Some of the best types of energy storage devices right now include lithium-ion batteries and supercapacitors. Research in this area has greatly improved electrode materials, enhanced electrolytes, and conceived clever designs for device assemblies with the ever-increasing energy and power density for electronics. Electrode materials are the fundamental key components for energy storage devices that largely determine the electrochemical performance of energy storage devices. Various materials such as carbon materials, metal oxides and conducting polymers have been widely used as electrode materials for energy storage devices, and great achievements have been made. Recently, metal nitrides have attracted increasing interest as remarkable electrode materials for lithium-ion batteries and supercapacitors due to their outstanding electrochemical properties, high chemical stability, standard technological approach and extensive fundamental importance. This review analyzes the development and progress of metal nitrides as suitable electrode materials for lithium-ion batteries and supercapacitors. The challenges and prospects of metal nitrides as energy storage electrode materials are also discussed.

Oxygen vacancy induced bismuth oxyiodide with remarkably increased visible-light absorption and superior photocatalytic performance.

With the increasingly serious environmental problems, photocatalysis has recently attracted a great deal of attention, with particular focus on water and air purification and disinfection. Herein, we show an electroreduction strategy to improve significantly the solar absorption and donor density of BiOI nanosheet photocatalyst by introducing oxygen vacancies. These oxygen-deficient BiOI nanosheets exhibit an unexpected red shift of about 100 nm in light absorption band and 1 order of magnitude improvement in donor density compared to the untreated BiOI nanosheets and show 10 times higher photocatalytic activity than the untreated BiOI nanosheets for methyl orange (MO) degradation under visible light irradiation. Moreover, the as-prepared oxygen-deficient BiOI nanosheets also have excellent cycling stability and superior photocatalytic performance toward other dye pollutants.

Water Surface Assisted Synthesis of Large‐Scale Carbon Nanotube Film for High‐Performance and Stretchable Supercapacitors

A kind of multiwalled carbon-nanotube (MWCNT)/polydimethylsiloxane (PDMS) film with excellent conductivity and mechanical properties is developed using a facile and large-scale water surface assisted synthesis method. The film can act as a conductive support for electrochemically active PANI nano fibers. A device based on these PANI/MWCNT/PDMS electrodes shows good and stable capacitive behavior, even under static and dynamic stretching conditions.

A monolithic metal-free electrocatalyst for oxygen evolution reaction and overall water splitting

Herein, a three-dimensional monolithic and metal-free N-doped porous carbon cloth electrocatalyst was fabricated. Owing to the increased surface area and N-doping, the self-supporting electrocatalyst could effectively catalyze the oxygen evolution reaction, and was also utilized as the anode for an alkaline electrolyzer for the first time with a considerably low overpotential.

Facile synthesis of titanium nitride nanowires on carbon fabric for flexible and high-rate lithium ion batteries

We demonstrate the good performance of TiN nanowires as anodes for lithium-ion batteries. TiN nanowires exhibit a high cycling performance with 80% capacity retention after 100 cycles at 335 mA g−1. Additionally, a full battery was fabricated with attractive flexibility and electrochemical performance.

Three-dimensional nickel nitride (Ni3N) nanosheets: free standing and flexible electrodes for lithium ion batteries and supercapacitors

The search for suitable electrode materials for electrochemical storage devices has led to the development of new electrode materials. Metal nitrides are regarded as an attractive and promising class of electrode materials for high-performance energy storage devices because they exhibit excellent electrical conductivity over the corresponding metal oxides and have considerably higher capacity than carbon based materials. Moreover, designing of different electrode nanostructures has been demonstrated to effectively improve the storage performance of energy storage devices. Hence, three dimensional (3D) nickel nitride (Ni3N) nanosheets were successfully fabricated on a carbon cloth by a simple hydrothermal and post annealing process that can be used directly as electrode storage materials for flexible lithium ion batteries and supercapacitors. Due to the electrode, architectures that demonstrated fast electron transport via direct connection to the flexible substrate and facile ion diffusion paths that ensured the participation of every nanosheet in the ultrafast electrochemical reaction, the 3D flexible Ni3N/carbon composites cloth exhibited a high capacity or capacitance and possessed an excellent rate performance.

A review of the development of full cell lithium-ion batteries: The impact of nanostructured anode materials

Lithium-ion batteries have emerged as the best portable energy storage device for the consumer electronics market. Recent progress in the development of lithiumion batteries has been achieved by the use of selected anode materials, which have driven improvements in performance in terms of capacity, cyclic stability, and rate capability. In this regard, research focusing on the design and electrochemical performance of full cell lithium-ion batteries, utilizing newly developed anode materials, has been widely reported, and great strides in development have been made. Nanostructured anode materials have contributed largely to the development of full cell lithium-ion batteries. With this in mind, we summarize the impact of nanostructured anode materials in the performance of coin cell full lithium-ion batteries. This review also discusses the challenges and prospects of research into full cell lithium-ion batteries.

Vanadium Nitride Nanowire Supported SnS2 Nanosheets with High Reversible Capacity as Anode Material for Lithium Ion Batteries

The vulnerable restacking problem of tin disulfide (SnS2) usually leads to poor initial reversible capacity and poor cyclic stability, which hinders its practical application as lithium ion battery anode (LIB). In this work, we demonstrated an effective strategy to improve the first reversible capacity and lithium storage properties of SnS2 by growing SnS2 nanosheets on porous flexible vanadium nitride (VN) substrates. When evaluating lithium-storage properties, the three-dimensional (3D) porous VN coated SnS2 nanosheets (denoted as CC-VN@SnS2) yield a high reversible capacity of 75% with high specific capacity of about 819 mAh g(-1) at a current density of 0.65 A g(-1). Remarkable cyclic stability capacity of 791 mAh g(-1) after 100 cycles with excellent capacity retention of 97% was also achieved. Furthermore, discharge capacity as high as 349 mAh g(-1) is still retained after 70 cycles even at a elevated current density of 13 A g(-1). The excellent performance was due to the conductive flexible VN substrate support, which provides short Li-ion and electron pathways, accommodates large volume variation, contributes to the capacity, and provides mechanical stability, which allows the electrode to maintain its structural stability.

Carbon Quantum Dot Surface-Engineered VO2 Interwoven Nanowires: A Flexible Cathode Material for Lithium and Sodium Ion Batteries

The use of electrode materials in their powdery form requires binders and conductive additives for the fabrication of the cells, which leads to unsatisfactory energy storage performance. Recently, a new strategy to design flexible, binder-, and additive-free three-dimensional electrodes with nanoscale surface engineering has been exploited in boosting the storage performance of electrode materials. In this paper, we design a new type of free-standing carbon quantum dot coated VO2 interwoven nanowires through a simple fabrication process and demonstrate its potential to be used as cathode material for lithium and sodium ion batteries. The versatile carbon quantum dots that are vastly flexible for surface engineering serve the function of protecting the nanowire surface and play an important role in the diffusion of electrons. Also, the three-dimensional carbon cloth coated with VO2 interwoven nanowires assisted in the diffusion of ions through the inner and the outer surface. With this unique architecture, the carbon quantum dot nanosurface engineered VO2 electrode exhibited capacities of 420 and 328 mAh g(-1) at current density rate of 0.3 C for lithium and sodium storage, respectively. This work serves as a milestone for the potential replacement of lithium ion batteries and next generation postbatteries.