New anode systems for lithium ion cells

Samples of small particle size bismuth and electroplated Ni-Sn alloy were t ested as anodes for lithium ion batteries to highlight the effects of volum e changes during charge and discharge on the cycling life of the electrodes . Bismuth was used for its relatively "high" potential of Li-Bi alloys form ation (0.8-0.6 V) which prevents other components within the electrode from being electrochemically active versus lithium in this potential window. El ectrochemical tests have shown that the capacity fade during cycling is lar gely dependant of the amount of Bi in the electrode. Electroplated Ni-Sn al loys were directly used as anodes and do not need to be reground nor mixed with additives. Different electroplating conditions, leading to different m orphology, highlight the leading role of the particle size of the active ma terials used in the lithium ion cells. (C) 2001 Elsevier Science B.V. All r ights reserved.