Pensacola, FL, United States
Pensacola, FL, United States

Time filter

Source Type

Biserni E.,Italian Institute of Technology | Biserni E.,Polytechnic of Milan | Scarpellini A.,Italian Institute of Technology | Bassi A.L.,Italian Institute of Technology | And 4 more authors.
Nanotechnology | Year: 2016

Nanoporous Si has been grown by pulsed laser deposition on a free-standing carbon nanotube (CNT) paper sheet for micro-battery anodes. The Si deposition shows conformal coverage on the CNT paper, and the Si-CNT paper anodes demonstrate high areal capacity of ∼1000 μAh cm-2 at a current density of 54 μA cm-2, while 69% of its initial capacity is preserved when the current density is increased by a factor 10. Excellent stability without capacity decay up to 1000 cycles at a current density of 1080 μA cm-2 is also demonstrated. After bending along the diameter of the circular paper disc many times, the Si-CNT paper anodes preserve the same morphology and show promising electrochemical performance, indicating that nanoporous Si-CNT paper anodes can find application for flexible micro-batteries. © 2016 IOP Publishing Ltd.


Wang Y.,University of Tennessee at Knoxville | Clancey J.,University of Colorado at Boulder | Lu G.,Shandong University | Liu J.,Shandong University | And 6 more authors.
Journal of the Electrochemical Society | Year: 2016

Platinum (Pt) decorated carbon nanotubes (CNTs) nanocatalysts (Pt/CNTs) were successfully prepared by an atomic layer deposition (ALD) method. Increased ratios of D to G band with increasing ALD cycles in Raman spectra suggested an interaction between Pt nanoparticles (NPs) and CNTs as well as increased Pt loadings. The absence of the Pt peaks in XRD before and after thermal annealing treatment demonstrated an ultra-small Pt NPs size. TEM revealed a perfect distribution of the ultra-small Pt NPs on the tube wall surface with different ALD cycles and an agglomeration of Pt NPs was observed when increasing the annealing temperature. Increased peak current density (jp) values in CV (25 cycles, denoted as Pt/CNTs-25C, 40.89 mA/mgPt, 50 cycles, Pt/CNTs-50C, 667.6 mA/mgPt and 100 cycles, Pt/CNTs-100C, 1205.7 mA/mgPt) were obtained toward the methanol oxidation reaction (MOR) with increasing the ALD cycles. 100 and 300°C hydrogen annealed Pt/CNTs-50C (denoted as Pt/CNTs-50C-100A and Pt/CNTs-50C-300A) gave increased and decreased jp values (1200 and 800 mA/mgPt) due to the positive hydrogen reduction of Pt(II)/Pt(IV) species and the negative Pt NPs agglomeration. Pt/CNTs-100C-100A exhibited the highest jp value (2000 mA/mgPt) after applying the optimal 100°C annealing treatment, enabling it an excellent candidate for MOR application. © The Author(s) 2015. Published by ECS.


Xie M.,Super Technologies Inc. | Piper D.M.,University of Colorado at Boulder | Tian M.,University of Colorado at Boulder | Clancey J.,University of Colorado at Boulder | And 3 more authors.
Nanotechnology | Year: 2015

Doped Si nanoparticles (SiNPs) with conformal carbon coating and cyclized-polyacrylonitrile (PAN) network displayed capacities of 3500 and 3000 mAh g-1 at C/20 and C/10, respectively. At 1 C, the electrode preserves a specific discharge capacity of ∼1500 mAh g-1 for at least 60 cycles without decay. Al2O3 atomic layer deposition (ALD) helps improve the initial Coulombic efficiency (CE) to 85%. The dual coating of conformal carbon and cyclized-PAN help alleviate volume change and facilitate charge transfer. Ultra-thin Al2O3 ALD layers help form a stable solid electrolyte interphase interface. © 2015 IOP Publishing Ltd.


Xie M.,Super Technologies Inc. | Sun X.,Rensselaer Polytechnic Institute | George S.M.,University of Colorado at Boulder | Zhou C.,Lawrence Technological University | And 2 more authors.
ACS Applied Materials and Interfaces | Year: 2015

Amorphous SnO2 (a-SnO2) thin films were conformally coated onto the surface of reduced graphene oxide (G) using atomic layer deposition (ALD). The electrochemical characteristics of the a-SnO2/G nanocomposites were then determined using cyclic voltammetry and galvanostatic charge/discharge curves. Because the SnO2 ALD films were ultrathin and amorphous, the impact of the large volume expansion of SnO2 upon cycling was greatly reduced. With as few as five formation cycles best reported in the literature, a-SnO2/G nanocomposites reached stable capacities of 800 mAh g-1 at 100 mA g-1 and 450 mAh g-1 at 1000 mA g-1. The capacity from a-SnO2 is higher than the bulk theoretical values. The extra capacity is attributed to additional interfacial charge storage resulting from the high surface area of the a-SnO2/G nanocomposites. These results demonstrate that metal oxide ALD on high surface area conducting carbon substrates can be used to fabricate high power and high capacity electrode materials for lithium-ion batteries. © 2015 American Chemical Society.


Xie M.,Super Technologies Inc. | Li B.,Super Technologies Inc. | Zhou Y.,Chongqing Normal University
Journal of Materials Chemistry A | Year: 2015

Lightweight, high-capacity and high-power LiCoO2 (LCO)/multi-wall carbon nanotube (MWCNT) free-standing electrodes are fabricated by a simple paper-making process. These electrodes have the highest LCO loading of 40 mg cm-2 reported in the literature, comparable to state-of-the-art battery mass loading. LCO/MWCNT paper electrodes have high flexibility, uniform material mass loading, low surface resistivity, and an outstanding rate capability of 142 mA h g-1 at 4C at 4.3 V. When coated with 2 cycle Al2O3 by ALD, LCO/MWCNTs attain high capacities of 179 mA h g-1 and 206 mA h g-1 at 4.5 V and 4.6 V, respectively. At 4.5 V, ALD coated LCO/MWCNTs preserves 95% of their initial capacity of 170 mA h g-1 at 1C after 85 cycles. A full cell with a LCO/MWCNT cathode shows a capacity retention of 77% after 500 deep cycles. By reducing the weight of electrodes and increasing the working voltage simultaneously, the LCO/MWCNT electrode structure can significantly improve the energy/power density of lithium ion batteries without changing the electrode material system, and therefore, has great potential to be used with ultrathin, ultralight consumer electronic devices as well as electric vehicles. © The Royal Society of Chemistry 2015.


Xie M.,Super Technologies Inc. | Xie M.,University of Colorado at Boulder | Sun X.,Rensselaer Polytechnic Institute | Sun H.,Rensselaer Polytechnic Institute | And 4 more authors.
Journal of Materials Chemistry A | Year: 2015

Amorphous V2O5 (a-V2O5) thin films were conformally coated onto the surface of hydroxyl (-OH) functionalized multi-walled carbon nanotubes (CNTs) and carbon nanotube (CNT) paper using atomic layer deposition (ALD). In order to achieve 3 Li+ intercalation (442 mA h g-1) and prevent V2O5 dissolution at 1.5 V, a conformal TiO2 protective layer is coated on the surface of V2O5/CNT. A free-standing paper electrode can be made by vacuum filtration or coating pre-fabricated CNT paper directly. The electrochemical characteristics of the TiO2/V2O5/CNT paper electrode were then determined using cyclic voltammetry and galvanostatic charge/discharge curves. Because the TiO2 and V2O5 ALD films were ultrathin, the poor electrical conductivity and low ionic diffusivity of V2O5 did not limit the ability of the V2O5 ALD films to display high specific capacity and high rate capability. A high discharge capacity of ∼400 mA h g-1 is obtained for 15 cycle ALD TiO2 coated 50 cycle ALD V2O5/CNT samples by depositing pre-fabricated CNT paper. We believe that this is the highest capacity for V2O5 cathodes reported in the literature. The capacities of the a-V2O5/CNT nanocomposites are higher than the bulk theoretical values. The extra capacity is attributed to additional interfacial charge storage resulting from the high surface area of the a-V2O5/CNT nanocomposites. These results demonstrate that metal oxide ALD on high surface-area conducting carbon substrates can be used to fabricate high power and high capacity electrode materials for lithium ion batteries. In addition, ultrathin and conformal TiO2 ALD coating can be used to mitigate the dissolution and capacity fading of the cathode. © 2016 The Royal Society of Chemistry.


PubMed | Chongqing Normal University, Super Technologies Inc., Rensselaer Polytechnic Institute, Lawrence Technological University and University of Colorado at Boulder
Type: Journal Article | Journal: ACS applied materials & interfaces | Year: 2015

Amorphous SnO2 (a-SnO2) thin films were conformally coated onto the surface of reduced graphene oxide (G) using atomic layer deposition (ALD). The electrochemical characteristics of the a-SnO2/G nanocomposites were then determined using cyclic voltammetry and galvanostatic charge/discharge curves. Because the SnO2 ALD films were ultrathin and amorphous, the impact of the large volume expansion of SnO2 upon cycling was greatly reduced. With as few as five formation cycles best reported in the literature, a-SnO2/G nanocomposites reached stable capacities of 800 mAh g(-1) at 100 mA g(-1) and 450 mAh g(-1) at 1000 mA g(-1). The capacity from a-SnO2 is higher than the bulk theoretical values. The extra capacity is attributed to additional interfacial charge storage resulting from the high surface area of the a-SnO2/G nanocomposites. These results demonstrate that metal oxide ALD on high surface area conducting carbon substrates can be used to fabricate high power and high capacity electrode materials for lithium-ion batteries.


Super Technologies Inc. | Entity website


Doped Si nanoparticles (SiNPs) with conformal carbon coating and cyclized-polyacrylonitrile (PAN) network displayed capacities of 3500 and 3000 mAh g(-1) at C/20 and C/10, respectively. At 1 C, the electrode preserves a specific discharge capacity of 1500 mAh g(-1) for at least 60 cycles without decay. Al2O3 atomic layer deposition (ALD) helps improve the initial Coulombic efficiency (CE) to 85%. The dual coating of conformal carbon and cyclized-PAN help alleviate volume change and facilitate charge transfer. Ultra-thin Al2O3 ALD layers help form a stable solid electrolyte interphase interface.

Loading Super Technologies Inc. collaborators
Loading Super Technologies Inc. collaborators