| Recently,the development of the use of secondary energy technology and method have become an important issue because of energy scarce.Hybrid capacitor combining high-energy and high-power has attracted more attention.It is one of the potential ways to find hybrid capacitor organic anode materials from lithium-ion battery materials.On the one hand,Li4Ti5O122 was prepared due normal solid method,choosing Li2CO3and TiO2 as raw materials.On the other hand,Li4Ti5O122 was synthesized by hydrothermal method,using Ti?OC4H9?4 and LiOH·H2O as raw materials.The effects of the parameters on the performance of Li4Ti5O122 were studied by changing the process parameters,dopant type and amount.The crystal structure and morphology of Li4Ti5O122 were characterized by XRD and SEM,respectively.The electrochemical performances of Li4Ti5O122 were tested by a land system and electrochemical workstation.Results show as follow:The pure phase Li4Ti5O122 can be prepared with Li2CO3excess 10wt%,and the performance is best at 750o C.Composite 2.5wt%CNTs and 2wt%glucose can make Li4Ti5O122 performance better.Its discharge capacity is 251.9 mAh·g-1at 20 mA·g-1;The discharge capacity is still 142.5 mAh·g-11 at 1 A·g-1.The specific power is 455.31 W·kg-1,while the specific energy is 37.9 Wh·kg-1,matching with AC as the hybrid capacitor.The performance is excellent,when the Li/Ti molar ratio is 4.2/5,and the reversible capacity reaches 73.12%after 1000 cycles at 1 A·g-11 in hydrothermal method.Its discharge capacity is stable at 129.1 mAh·g-1after 1000 cycles at 2 A·g-1at 650oC,and the capacity retention rate is 77.21%;adding 0.08 mol C4H6CoO4,its discharge capacity can reach 144.6 mAh·g-11 after 1000 cycles at 2 A·g-11 with 92.17%capacity retention rate.The specific power increases from 59.86 W·kg-1to 465.14 W·kg-1,while the specific energy can still reach 61.1 Wh·kg-1,matching with AC as the hybrid capacitor.Figure 50;Table 11;Reference 66... |
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