Structured Electrode Additive Manufacturing for Lithium-Ion Batteries

As the world increasingly swaps fossil fuels, significant advances in lithium-ion batteries have occurred over the past decade. Though demand for increased energy density with mechanical stability continues to be strong, attempts to use traditional ink-casting to increase electrode thickness or geometric complexity have had limited success. Here, we combined a nanomaterial orientation with 3D printing and developed a dry electrode processing route, structured electrode additive manufacturing (SEAM), to rapidly fabricate thick electrodes with an out-of-plane aligned architecture with low tortuosity and mechanical robustness. SEAM uses a shear flow of molten feedstock to control the orientation of the anisotropic materials across nano to macro scales, favoring Li-ion transport and insertion. These structured electrodes with 1 mm thickness have more than twice the specific capacity at 1 C compared to slurry-cast electrodes and have higher mechanical properties (compressive strength of 0.84 MPa and modulus of 5 MPa) than other reported 3D-printed electrodes

Structured Electrode Additive Manufacturing for Lithium-Ion Batteries

As the world increasingly swaps fossil fuels, significant advances in lithium-ion batteries have occurred over the past decade. Though demand for increased energy density with mechanical stability continues to be strong, attempts to use traditional ink-casting to increase electrode thickness or geometric complexity have had limited success. Here, we combined a nanomaterial orientation with 3D printing and developed a dry electrode processing route, structured electrode additive manufacturing (SEAM), to rapidly fabricate thick electrodes with an out-of-plane aligned architecture with low tortuosity and mechanical robustness. SEAM uses a shear flow of molten feedstock to control the orientation of the anisotropic materials across nano to macro scales, favoring Li-ion transport and insertion. These structured electrodes with 1 mm thickness have more than twice the specific capacity at 1 C compared to slurry-cast electrodes and have higher mechanical properties (compressive strength of 0.84 MPa and modulus of 5 MPa) than other reported 3D-printed electrodes

Intertwined Network of Si/C Nanocables and Carbon Nanotubes as Lithium-Ion Battery Anodes

We demonstrate a new kind of Si-based anode architectures consisting of silicon nanowire/overlapped graphene sheet core–sheath nanocables (SiNW@G) intertwined with carbon nanotubes (CNTs). In such a hybrid structure, the CNTs, mechanically binding SiNW@G nanocables together, act as a buffer matrix to accommodate the volume change of SiNW@G, and overlapped graphene sheets (that is, G sheaths) effectively prevent the direct contact of silicon with the electrolyte during cycling, both of which enable the structural integrity and interfacial stabilization of such hybrid electrodes. Furthermore, the one-dimensional nature of both components affords the creation of a three-dimensional interpenetrating network of lithium ion and electron pathways in the resultant hybrids, thereby enabling efficient transport of both electrons and lithium ions upon charging/discharging. As a result, the hybrids exhibit much-improved lithium storage performance

MWCNT/V₂O₅ Core/Shell Sponge for High Areal Capacity and Power Density Li-Ion Cathodes

A multiwall carbon nanotube (MWCNT) sponge network, coated by ALD V₂O₅, presents the key characteristics needed to serve as a high-performance cathode in Li-ion batteries, exploiting (1) the highly electron-conductive nature of MWCNT, (2) unprecedented uniformity of ALD thin film coatings, and (3) high surface area and porosity of the MWCNT sponge material for ion transport. The core/shell MWCNT/V₂O₅ sponge delivers a stable high areal capacity of 816 μAh/cm² for 2 Li/V₂O₅ (voltage range 4.0–2.1 V) at 1C rate (1.1 mA/cm²), 450 times that of a planar V₂O₅ thin film cathode. At much higher current (50×), the areal capacity of 155 μAh/cm² provides a high power density of 21.7 mW/cm². The compressed sponge nanoarchitecture thus demonstrates exceptional robustness and energy-power characteristics for thin film cathode structures for electrochemical energy storage

Distribution of different family strains in Northern and Southern regions.

†<p>The number of isolates.</p>‡<p>According to Chinese administrative division, the Northern region of China includes provinces as followed: Heilongjiang, Jilin, Liaoning, Inner Mongolia, Hebei, Beijing, Tianjin, Shandong, Henan, Shanxi, Shaanxi, Ningxia, Gansu, Qinghai and Xinjiang.</p>§<p>According to Chinese administrative division, the Southern region of China includes provinces as followed: Jiangsu, Anhui, Hunan, Sichuan, Yunnan, Guizhou, Guangdong, Guangxi, Fujian, Jiangxi, Zhejiang, Hainan, Xizang, Shanghai and Chongqing.</p>*<p>: P<0.05 (significant);</p>**<p>: P<0.01 (highly significant);</p>***<p>: P<0.001 (extremely significant).</p

Prevalence of 10 most common Spoligotyping types annotated in SpolDB4.0.

*<p>SIT from SpolDB4.0.</p>†<p>Representing spoligotype families annotated in SpolDB4.0.</p>‡<p>Number of strains with the same SIT.</p>§<p>Prevalence represents the percentage of isolates with a common SIT among all isolates in this study.</p>¶<p>NA represents the spoligotyping type which is not found in SpoIDB4.0.</p

Prevalence of antituberculosis drug resistance among the most popular genotypes in China TB survilliance.

†<p>SIT from SpolDB4.0.</p>‡<p>Representing spoligotype families annotated in SpolDB4.0.</p>§<p>Number of isolates with both the same SIT and results of drug sensitive test.</p>¶<p>MDR, multidrug resistant, represents isolates resistant to at least isonazid and rifampin.</p>*<p>: P<0.05 (significant);</p>**<p>: P<0.01 (highly significant);</p>***<p>: P<0.001 (extremely significant).</p

Distribution map of M. tuberculosis isolates included in this study.

<p>The provinces colored with red represent the northern region of China including Heilongjiang, Jilin, Liaoning, Inner Mongolia, Hebei, Beijing, Tianjin, Shandong, Henan, Shanxi, Shaanxi, Ningxia, Gansu, Qinghai and Xinjiang. And the provinces colored with yellow represent the southern region of China including Jiangsu, Anhui, Hunan, Sichuan, Yunnan, Guizhou, Guangdong, Guangxi, Fujian, Jiangxi, Zhejiang, Hainan, Xizang, Shanghai and Chongqing.</p

Tailoring Carbon Nanotube Density for Modulating Electro-to-Heat Conversion in Phase Change Composites

We report a carbon nanotube array-encapsulated phase change composite in which the nanotube distribution (or areal density) could be tailored by uniaxial compression. The <i>n</i>-eicosane (C20) was infiltrated into the porous array to make a highly conductive nanocomposite while maintaining the nanotube dispersion and connection among the matrix with controlled nanotube areal density determined by the compressive strains along the lateral direction. The resulting electrically conductive composites can store heat at driven voltages as low as 1 V at fast speed with high electro-to-heat conversion efficiencies. Increasing the nanotube density is shown to significantly improve the polymer crystallinity and reduce the voltage for inducing the phase change process. Our results indicate that well-organized nanostructures such as the nanotube array are promising candidates to build high-performance phase change composites with simplified manufacturing process and modulated structure and properties

Meter-Long Spiral Carbon Nanotube Fibers Show Ultrauniformity and Flexibility

Conventional straight fibers spun from carbon nanotubes have rather limited deformability; creating a spiral structure holds the promise to break this shape restriction and enhance structural flexibility. Here, we report up to one meter-length threads containing purely single-walled nanotubes twisted into spiral loops (about 1.3 × 10⁵ loops per meter) with tunable fiber diameters and electrical conductivity. Because of significant increase of the loop number and long-range homogeneity, the fibers display many unique properties (e.g., self-shrinking and forming extremely entangled structure, fast stretching with great resilience, large-degree axial and lateral deflection, and excellent fatigue resistance) that are difficult to achieve in straight yarns or short helical segments. They also have potential applications as macroscopic fiber-shaped temperature sensors and deformable gas sensors. Our long spiral fibers may be configured into versatile structures such as nanotextiles for developing wearable electronics and multifunctional fabrics