more than four decades ago with a TiS 2based cathode prototype battery, [ 3 ] which was followed shortly thereafter by Moli Energy's brief commercialization of a Li/ MoS 2 battery. Unfortunately, prodigious battery capacity losses were observed when Li metal was used as the anode, especially for high current density charging, which resulted in rapid cell failure and safety concerns. Li metal was therefore replaced with carbon coke and later graphitic carbon as an anode. Subsequently, intercalation cathode materials, such as LiCoO 2 and LiFePO 4 , were then discovered and these, in concert with graphitic carbon, now form the foundation of today's Li-ion batteries. [ 4,5 ] In general, however, Li metal continues to be used in three different categories for battery systems: 1) as a counter electrode in half-cells to evaluate the properties of cathode or anode materials such as LiNi 1/3 Mn 1/3 Co 1/3 O 2 or Si, respectively; 2) as an anode to study cathode materials such as V 2 O 5 , which have no Li source in the lattice; and 3) as an anode for next-generation, high-energy storage technologies such as Li-S and Li-O 2 batteries, as well as Li-S hybrid redox fl ow batteries. 7-9 For these high-energy systems, the Li metal is indispensable, thus marking the importance of obtaining a fundamental understanding of the Li metal failure mechanism during cell cycling.When compared with the original pristine, dense Li metal, the redeposited Li always displays a signifi cantly different morphology, i.e., mossy Li. In addition, some of the redeposited Li may gradually or suddenly lose electrical contact with the bulk material thus becoming inactive in the cell after repeated cycling. [ 6 ] The morphological transformation from dense to porous Li metal also leads to the uneven distribution of the electric fi eld in the Li anode resulting in an evolution in the electrochemical reactions during subsequent electrode cycling, further accelerating the inhomogeneous Li deposition. The end result is generally reported to be the growth of dendritic Li metal, which protrudes from the anode surface leading to cell shorting when contact is made with the cathode. [ 7,8 ] Much effort has been devoted to preventing this dendrite growth. A few common strategies can be identifi ed, including the 1) formation of Li-Al or Li-Mg alloys, [ 2,9 ] 2) use In recent years, the Li metal anode has regained a position of paramount research interest because of the necessity for employing Li metal in nextgeneration battery technologies such as Li-S and Li-O 2 . Severely limiting this utilization, however, are the rapid capacity degradation and safety issues associated with rechargeable Li metal anodes. A fundamental understanding of the failure mechanism of Li metal at high charge rates has remained elusive due to the complicated interfacial chemistry that occurs between Li metal and liquid electrolytes. Here, it is demonstrated that at high current density the quick formation of a highly resistive solid electrolyte interphase (SEI) entangled with Li metal,...

The Endangered Species Act requires actions that improve the passage and survival rates for migrating salmonoids and other fish species that sustain injury and mortality when passing through hydroelectric dams. To develop a low-cost revolutionary acoustic transmitter that may be injected instead of surgically implanted into the fish, one major challenge that needs to be addressed is the micro-battery power source. This work focuses on the design and fabrication of micro-batteries for injectable fish tags. High pulse current and required service life have both been achieved as well as doubling the gravimetric energy density of the battery. The newly designed micro-batteries have intrinsically low impedance, leading to significantly improved electrochemical performances at low temperatures as compared with commercial SR416 batteries. Successful field trial by using the micro-battery powered transmitters injected into fish has been demonstrated, providing an exemplary model of transferring fundamental research into practical devices with controlled qualities.

Specifically designed micro-batteries have been developed for injectable fish tags. Through appropriate lamination and fabrication process, cylindrical CFx-based micro-batteries have been prepared in the lab readily for mass production. High pulse current and required service life have both been achieved as well as doubling the gravimetric energy density of the battery. The newly designed micro-batteries have intrinsically low impedance, leading to significantly improved electrochemical performances at low temperatures. Successful field trial by using the micro-battery powered transmitters injected into fish has been demonstrated, providing an exemplary model of transferring fundamental research into practical devices with controlled qualities.

Contributed by significantly improved solid/liquid interface and kinetics of Li+ diffusion, nanostructured electrode materials offer wide and promising applications in Li-ion and rechargeable lithium batteries, especially for the high power demand.[1] For example, by embedding electronic insulating sulfur into the nanostructured carbon frameworks, the obtained sulfur/carbon composites deliver high capacity and greatly improved cycling stability as cathode.[2, 3] Similarly, silicon exhibits outstanding properties as promising anode for Li-ion batteries after reduced to nanosize or combined with carbon by forming Si/C composites.[4] Despite these superiorities of nanosized novel structures, materials in nano-scale still face the challenge with respect to the practical applications in batteries. Besides side reactions initiating on the high surface electrode, it is difficult to achieve high loading electrode with nanosized active materials through slurry coating technique due to the generation of sever cracking or pinholes during the drying process. One of the reasons behind this phenomenon is the large volume shrink of nanosized materials accompanying the solvent removing from slurry. These downsides have plagued the practical application of nano-sized materials in energy storage systems. Attempts have been made to address these issues by increasing the particle size through spray drying, introducing conductive polymer or other self-assemble approaches, which are either complicated with special equipment or not cost-effective for large scale applications. We herein propose a facile and up-scale available approach to coat nano particles into electrodes with practically usable thickness and active mass loadings. Successful demonstration of this approach was shown in sulfur and silicon nano particles. High loading but crack-free coating for sulfur (loading: 2-8 mg sulfur/cm2) and Si (loading: 2-4 mg Si/ cm2) electrodes have been displayed. In addition, we did detailed screen for the binder selection and slurry composition modification. Base on the obtained high loading electrodes, systematical study was performed on the relationships of electrode loading, pressure, energy density and rate capability. All these obtained results will be presented at the meeting. References [1] A. S. Arico; P. Bruce; B. Scrosati; J. M. Tarascon; W. Van Schalkwijk, Nature Materials 2005, 4, 366. [2] X. Ji; K. T. Lee; L. F. Nazar, Nature Materials 2009, 8, 500. [3] J. Zheng; M. Gu; M. J. Wagner; K. A. Hays; X. Li; P. Zuo; C. Wang; J.-G. Zhang; J. Liu; J. Xiao, Journal of the Electrochemical Society 2013, 160, A1624. [4] C. K. Chan; H. Peng; G. Liu; K. McIlwrath; X. F. Zhang; R. A. Huggins; Y. Cui, Nature Nanotechnology 2008, 3, 31.