A facile and scalable method is reported to fabricate Si-graphene nanocomposite as anode material for Li-ion batteries (LIBs) with high capacity and capacity retention performance. The Si-graphene electrode showed an initial discharge capacity of 1307 mAh g−1 at a current rate of 0.1C. At the 25th cycle, the electrode retained a discharge capacity of 1270 mAh g−1, with an excellent capacity retention of 97%. At the 50th cycle, the electrode still retained high capacity retention of 89%. The improved capacity retention of Si-graphene anode compared with Si anode is attributed to the mechanical flexibility of graphene that compromises the volume expansion of Si during the lithiation/delithiation process. The electrochemical impedance measurement further confirms the enhanced electrical conductivity and the denser solid-electrolyte-interface of the Si-graphene electrode. This fabrication approach is cost-effective and easy to scale up compared to known techniques, making it a promising candidate for commercializing Si-based anode for LIBs.
Carbon nanotubes and nanofibers (CNFs) are well-known nano additives to produce coating materials with high electrical and thermal conductivity and corrosion resistance. In this paper, coating materials incorporating hydrogen bonding offered significantly lower electrical resistance. The hydrogen bonding formed between functionalized carbon nanotubes and ethanol helped create a well-dispersed carbon nanotube network as the electron pathways. Electrical resistivity as low as 6.8 Ω cm has been achieved by adding 4.5 wt% functionalized multiwalled carbon nanotubes (MWNT-OH) to 75%polyurethane/25%ethanol. Moreover, the thermal conductivity of polyurethane was improved by 332% with 10 wt% addition of CNF. Electrochemical methods were used to evaluate the anti-corrosion properties of the fabricated coating materials. 75%polyurethane/25%ethanol with the addition of 3.0 wt% of MWNT-OH showed an excellent corrosion rate of 5.105 × 10 –3 mm year −1 , with a protection efficiency of 99.5% against corrosive environments. The adhesion properties of the coating materials were measured following ASTM standard test methods. 75%polyurethane/25%ethanol with 3.0 wt% of MWNT-OH belonged to class 5 (ASTM D3359), indicating the outstanding adhesion of the coating to the substrate. These nanocoatings with enhanced electrical, thermal, and anti-corrosion properties consist of a choice of traditional coating materials, such as polyurethane, yielding coating durability with the ability to tailor the electrical and thermal properties to fit the desired application.
The increasing demand for lithium-ion batteries (LIBs) continuously stimulates the research community to seek advanced fabrication of anodes with improved performance and lifespan. Silicon (Si), as one of the most promising anode materials, has been the main focus of both research and industry. In this paper, we report a type of Si alloy anode for LIBs manufactured by the supersonic cold spray technique. The microscopic analysis revealed the uniform morphologies of the anodes, indicating that Si and other metal particles were well bonded. Specific discharge capacities were obtained for the cold-sprayed anodes by half-coin cell tests, with the highest value of 1047 mAh g−1 at a current rate of 0.05 C. Most importantly, the energy-dispersive x-ray spectroscopy results demonstrated none oxidation of the powders after the cold spray process. The results strongly indicate that the concept of using cold spray technique to fabricate Si alloy anode is feasible. Compared to the conventional methods of fabricating Si anodes, the cold spray approach is simple, convenient, and scalable. This method may revolutionarily change the LIBs industries.
Electronics depend on their ability to shed operational heat to maintain operating temperature. Inferior grease can create preventable problems in electronics. This is typically achieved through a thermal grease or paste. If this grease fails to dissipate heat or maintain thermal contact, then the equipment will have faults. Greases with less-than-optimal performance create excessive wear, heat, and reduced life expectancy. This can cause equipment failures and malfunctions at the most inopportune moments. Thermal greases are applied to Central Processors (CPU) and Graphics Processors (GPU) in avionics LRUs, computers, Solar panels, HVAC systems, and other electronics. A high-performance novel nano grease will shed excess heat and increase device life expectancy. The fabricated nano greases show improvements of up to 80% in thermal conductivity measurements. CPU testing resulted in a 100% decrease in the standard deviation of temperature variation from commercial greases.
Internal combustion engines remain a predominant source of global energy consumption, contributing substantially to both operational costs and greenhouse gas emissions. This work evaluates a nanomaterial-based engine oil additive that reduces friction and wear and increases torque, horsepower, and fuel efficiency. This novel nano oil additive contains functionalized carbon nanotubes and hexagonal boron nitride nanosheets that are dispersed in base oil using a proprietary ultrasonication process. Block-on-ring tests performed by multiple testing facilities demonstrated up to a 17% decrease in coefficient of friction and up to a 78% decrease in wear compared to the base oil after treating with the nano oil additive. Thermal properties enhancement by the nano oil additive was evaluated and increases up to 17 °C in thermal stability were obtained. Additionally, the nano oil additive increased torque and horsepower by an average of 7% in motorcycles and 2.4% in pickup trucks. Most importantly, the nano oil additive demonstrated improvements in fuel economy in both gasoline and diesel engines, with laboratory tests reporting 3–5% increases and practical field tests on a commercial truck fleet reporting an average of a 6% increase. The improved engine efficiency leads to reduced turbo temperature in heavy diesel engines and prolonged engine life expectancy and will significantly improve global environmental sustainability.