Electrochemical measurements, including a.c. and d.c. techniques, were performed in order to determine the differences between Li-B alloy prepared at 600 degrees C and Li-B composite prepared at 450 degrees C. Li-B composites can be defined as very finely-grained, physically dispersed amorphous boron, entrapped in polycrystalline metallic lithium. SEM analysis of electrode surfaces, corroborating the electrochemical measurements, is given. Some experimental problems arising from passive layer formation on lithium in organic electrolytes which influence the reliability and reproducibility of the results are discussed.