Gel polymer electrolyte combined lignocellulose with sodium alginate in lithium-ion battery

The adoption of gel polymer electrolyte (GPE) is a solution to efficiently solve the serious security risk of lithium-ion batteries (LIBs). GPE based on lignocellulose (LC) and sodium alginate (SA) was prepared. When the proportion of SA reaches up to 20 wt.%, the obtained composite membrane has a liquid electrolyte uptake of 337 wt.% and a porosity of 58%, and its mechanical strength is over four times than that of pure LC-based membrane. In addition, the corresponding GPE with 20 wt.% SA (GLCSA-20) presents high lithium-ion transference number of 0.76, distinguished ion conductivity of 2.70 × 10[Formula: see text] S cm[Formula: see text], excellent discharge specific capacity (124 mAh cm[Formula: see text] at 1 C when 200th cycle of Li∥GLCSA-20∥LiFePO[Formula: see text] and outstanding cyclic stability. These virtues support that the GLCSA-20 has great potential for applications in safe LIBs.

Coherent Precipitates as a Condition for Ultra-Low Fatigue in Cu-Rich Ti53.7Ni24.7Cu21.6 Shape Memory Alloys

Sputtered Ti–rich TiNiCu alloys are known to show excellent cyclic stability. Reversibility is mostly influenced by grain size, crystallographic compatibility and precipitates. Isolating their impact on cyclic stability is difficult. Ti2Cu precipitates for instance are believed to enhance reversibility by showing a dual epitaxy with the B2 and B19 lattice. Their influence on the functional fatigue, if they partly lose the coherency is still unknown. In this study, sputtered Ti53.7Ni24.7Cu21.6 films have been annealed at different temperatures leading to a similar compatibility (λ2 ~ 0.99), grain size and thermal cyclic stability. Films annealed at 550 °C exhibit a superior superelastic fatigue resistance but with reduced transformation temperatures and enthalpies. TEM investigations suggest the formation of Guinier–Preston (GP) zone-like plate precipitates and point towards a coherency relation of the B2 phase and finely distributed Ti2Cu precipitates (~ 60 nm). Films annealed at 700 °C result in the growth of Ti2Cu precipitates (~ 280 nm) with an irregular distribution and a partial loss of their coherency. Thus, GP zones are assumed to cause the reduction of transformation temperatures and enthalpies due to increased internal stresses, whereas the coherency relation of both, Ti2Cu and GP zones, help to increase the superelastic stability, well beyond 107 cycles.