Improved electrochemical properties in the Li_3Fe_2(PO_4)_3 by titanium and vanadium doping

The nominal Li_(3-x)Fe_(2-x)Ti_x(PO_4)_(2.55)(VO_4)_(0.45)(x=0～0.3) compounds were synthesized by a sol-gel process.Different from the single V043 doping, further introduction of Ti^(4+) ion was easy to result in precipitation of a little secondary phases, besides the main NASICON products. The simultaneous substitution of Ti^(4+)and VO_4~3 for Fe^(3+) and PO_4~3,respectively, in the Li_3 Fe_2(PO_4)_3 resulted in a net improvement in the rate capability and cycling performance, as compared with the single Ti^(4+) or VO_4~3-substituted compound.The sample with x=0.2 presented a high initial discharging capacity of 125.4 mAh/g at the rate of 0.5 C,about 25% higher than the Ti^(4+)-substituted Li_(2.8)Fe_(1.8)Ti_(0.2)(PO_4)_3, and 102.6 mAh/g after 60 cycles at 2 C,about 12% higher than the single VO_4~3-substituted one. The high rate performance between 0.5 C to 10 C suggested that this sample had a good stability and reversibility. These results proved that the combination of the Ti^(4+) substitution for Fe^(3+) with the V043 substitution for PO_4~3 was a promising method of improving electrochemical performance of the studied Li_3 Fe_2(PO_4)_3 cathode material.

Price squeeze under fairness: the road to supply chain coordination with a powerful retailer

This research investigates the impacts of the manufacturer’s fairness concerns on the supply chain performance when the power retailer implements a price squeeze and market service investment together.Through game-theoretic modeling,we find that 1)in the absence of fairness,although the manufacturer may be worse off due to possessing imperfect information on the price squeeze rate,the channel may be coordinated through an ex-ante negotiation between the two parties.2)When the manufacturer has fairness concerns for price squeeze,both channel performance and brand goodwill are made worse by disadvantageous inequality and improved by advantageous inequality versus the case of no fairness concerns.Furthermore,channel members’ex-ante negotiations regarding a profit reallocation scheme under certain conditions may achieve the following three objectives:generating a channel profit of the coordination level,promoting brand goodwill to the level of the integrated channel,and creating an equitable channel relationship.