Design of Battery Electrodes with Dual‐Scale Porosity to Minimize Tortuosity and Maximize Performance

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96689/1/1254_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/96689/2/adma_201204055_sm_suppl.pd

Li/ Li1+xV3O8 batteries. V°. Comparison with other secondary cells and influence of micro- and macro-structural alteration on the cathode performance.

Li/Li1+xV3O8 cells have been compared with analogous cells based on TiS2, V6O13 and β-Na0.17V2O5 cathode. The results have demonstrated thet this bronze can be ranked among the most promising cathode materials for high rate rechargeable Li cells. This has encouraged attempts aimed at improving the electrochemical performance of the bronze through substitution of V witch such transition metals as Cr and Mo, and substitution of Li with Na. None of these substituted materials performed better thet the parent compound. On the other hand, controlled H2O Intercalation within the layers resulted in an increased interlayer distance and in higher capacities. A remarkable improvement in cell performance at high rate (10 mA/Cm2) was obtained with a new technique of cathode preparation

Li/ Li1+xV3O8 secondary batteries. IV°. Evaluation of factors affecting the performance of test cells.

With the aim of optimizing the performance of Li/Li1+xV3O8 cells, several aspects of cathode preparation have been examined. The influence of synthesis technique nature and amount of conductive additive, compacting pressure, cathode loading, and particle size, has been investigated. Furthermore, the role played by the solutions on cathode efficiency has been outlined. The formulations which perform best are based on small-sized particles blended with about 20% acetylene black and compacted at very high pressures to improve the contact between particles. Such cathodes can provide high capacities at high rate and good cycling efficiencies. The Kinetic loss of capacity, observed during the first few cycles, may be alleviated by choosing solutions with high fluidity and conductivity