Li[Lil/zTi~/3]O ~ having a defect spinel-framework structure (Fd3m; a = 8.36 A) was prepared and examined in nonaqueous lithium cells. Li[Li~/~Ti~/3]O 4 (white in color) was reduced to Li2[Lil/~Tij/3104 (dark blue) at a voltage of 1.55 V and the reaction was highly reversible. X-ray diffraction measurements indicated that the lattice dimension did not change during the reaction Li[Lil/~Tis/3]O4 + Li + + e .... L12[Lll/3Ti5 3]O4 8(a) 16(d) 32(e) ~16(c) 16(d)/32(e)Since the reaction consists of lithium ion and electron insertion into/extraction from the solid matrix without a noticeable change in lattice dimension, called a zero-strain insertion reaction, capacity failure due to the damage to the solid matrix was not observed even after 100 cycles. Feasibility of zero-strain insertion materials for advanced batteries is discussed based on the experimental results.

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The kinetics of structural relaxation in Pd 42.5 Cu 30 Ni 7.5 P 20 bulk metallic glass (BMG) was investigated by means of volume relaxation and enthalpy relaxation in the temperature range below T g (µ 573 K). The measured relaxation time was significantly longer than the ¡-relaxation time reported by dynamical mechanical analysis (DMA), indicating that these two relaxation processes are fundamentally different from each other. The temperature dependence of electrical resistivity suggests that the origin of the ¢-relaxation process that occurs between room temperature and T g may be the compositional short range ordering. Anomalous volume expansion was observed in the initial stage of relaxation, which was attributed to annihilation of the p-type defects with very short relaxation time.