Shu Luo

Binder‐Free LiCoO2/Carbon Nanotube Cathodes for High‐Performance Lithium Ion Batteries

Binder-free LiCoO(2) -SACNT cathodes with excellent flexibility and conductivity are obtained by constructing a continuous three-dimensional super-aligned carbon nanotube (SACNT) framework with embedded LiCoO(2) particles. These binder-free cathodes display much better cycling stability, greater rate performance, and higher energy density than classical cathodes with binder. Various functional binder-free SACNT composites can be mass produced by the ultrasonication and co-deposition method described in this paper.

Entrapping electrode materials within ultrathin carbon nanotube network for flexible thin film lithium ion batteries

A novel design of a flexible thin film electrode for lithium ion batteries is reported. We employ ordered carbon nanotube (CNT) film, directly pulled from aligned CNT arrays, as a flexible skeleton. The functional electrode material is introduced by a one-step spray-painting approach. The electrode is self-sustained as a result of the strong interactions among CNTs. In such an electrode configuration, the CNT network acts as micro electron pathways and its excellent mechanical properties also ensure flexibility. The electrodes fabricated in this way are electrochemically and mechanically superior in comparison with those prepared by the traditional slurry cast method. A full battery that contains a LiFePO4 cathode and a Li4Ti5O12 anode exhibits a high areal capacity over 200 μA h cm−2, a stable output voltage of 1.82 V, excellent reversibility, high flexibility, and light polarization in both flat and bent conditions. As a result, we suggest such electrodes hold great promise for thin film lithium ion batteries to satisfy energy storage demand in revolutionary portable electronics.

Self‐assembly of 3D Carbon Nanotube Sponges: A Simple and Controllable Way to Build Macroscopic and Ultralight Porous Architectures

Macroscopic and 3D superaligned CNT (SACNT) sponges are fabricated through a simple, low-cost, controllable, and scalable self-assembly method without using organic binder. Sponges with specific shapes and densities can be achieved. SACNT sponges are ultralight (1-50 mg cm-3 ), highly porous (97.5%-99.9%) with honeycomb-like hierarchical structure, and highly conductive. Using SACNT sponges as templates, various materials with honeycomb-like structure can be obtained for wide applications.

Sandwich-structured cathodes with cross-stacked carbon nanotube films as conductive layers for high-performance lithium-ion batteries

A simple and feasible strategy of using cross-stacked super-aligned carbon nanotube (SACNT) films as conductive layers to prepare sandwich-structured LiCoO2 cathodes for high-performance lithium-ion batteries (LIBs) is reported. Owing to the super-aligned feature, the SACNTs are fully dispersed and form a homogeneous and efficient conductive network in the electrodes. Meanwhile, the sandwiched electrode structure, consisting of a repeating and alternating stack of LiCoO2 layers and SACNT films, ensures that each layer of active materials can adhere to the SACNT conductive layers, realizing sufficient electron transfer throughout the electrodes regardless of the thickness of the electrodes. With the introduction of three separate SACNT conductive layers, significant improvements on the conductivity as well as the cell performance are achieved. The sandwich-structured LiCoO2–2 wt% Super P–SACNT cathodes possess an impressive rate capability (109.6 mA h g−1 at 10C and 1668% improvement compared with that without SACNT films), showing the best rate performances reported so far for commercial micro-sized LiCoO2 particles. The easy fabrication procedure, compatible method for commercialization, low cost, and outstanding electrochemical performances of the sandwich-structured electrode demonstrate its great potential for the large-scale production of high-performance electrodes for LIBs.

Self-Expansion Construction of Ultralight Carbon Nanotube Aerogels with a 3D and Hierarchical Cellular Structure

A novel and simple strategy is developed to construct ultralight and 3D pure carbon nanotube (CNT) aerogels by the spontaneous expansion of superaligned CNT films soaked in a piranha (mixed H2 SO4 and H2 O2 ) solution, followed by cryodesiccation. The macroscopic CNT aerogels have an extremely low apparent density (0.12 mg cm-3 ), ultrahigh porosity (99.95%), high specific surface area (298 m2 g-1 ), and a hierarchical cellular structure with giant and ultrathin CNT sheets as cell walls. The pure CNT aerogels show high adsorption abilities for various kinds of solvents, and have great potential in widespread applications such as energy storage, catalysis, and bioengineering.

Synergistic effect of manganese oxide nanoparticles and graphene nanosheets in composite anodes for lithium ion batteries

A graphene-Mn3O4-graphene (GMG) sandwich structure with homogeneous anchoring of Mn3O4 nanoparticles among flexible and conductive graphene nanosheets (GSs) is achieved through dispersion of the GSs in Mn(NO3)2 solution and subsequent calcination. Mn3O4 nanoparticles are 50 ~ 200 nm clusters consisting of 10 ~ 20 nm primary particles, and serve as spacers to prevent the re-stacking of the GSs. GSs provide a highly conductive network among Mn3O4 nanoparticles for efficient electron transfer and buffer any volume change during cycling. Due to the strong synergistic effect between Mn3O4 and GSs, the capacity contributions from GSs and Mn3O4 in GMG are much larger than capacities of pure GSs and Mn3O4. Consequently, the GMG composite electrodes show excellent electrochemical properties for lithium ion battery applications, demonstrating a large reversible capacity of 750 mAh g−1 at 0.1 C based on the mass of GMG with no capacity fading after 100 cycles, and high rate abilities of 500 mAh g−1 at 5 C and 380 mAh g−1 at 10 C.