López María C, Ortiz Gregorio F, González José R, Alcántara Ricardo, Tirado José L
Laboratorio de Química Inorgánica, Universidad de Córdoba , Edificio Marie Curie, Campus de Rabanales, 14071 Córdoba, Spain.
ACS Appl Mater Interfaces. 2014 Apr 23;6(8):5669-78. doi: 10.1021/am500189h. Epub 2014 Apr 11.
Self-organized TiO2 nanotubes ranging from amorphous to anatase structures were obtained by anodization procedures and thermal treatments at 500°C. Then electrolytic Li3PO4 films were successfully deposited on the nanotube array by an electrochemical procedure consisting in proton reduction with subsequent increase in pH, hydrogen phosphate dissociation and Li3PO4 deposition on the surface of the cathode. The Li3PO4 polymorph (γ or β) in the deposit could be tailored by modifying the electrodeposition parameters, such as time or current density, as determined by X-ray patterns. The morphological analysis evidenced the formation of a 3D nanostructure consisting of Li3PO4 coating the TiO2 nanotube array. The anode-solid electrolyte stacking was tested in lithium half cells. Interestingly, the electrochemical performances revealed a better cycling stability for samples containing low amount of lithium phosphate, which is deposited for short times and low current densities. These results suggested the possibility of fabricating 3D Li-ion batteries. nt-TiO2/γ-Li3PO4/LiFePO4 full cells were cycled at different rates in the C/5-5C range. This cathode-limited microbattery delivered a reversible gravimetric capacity of 110 mA h g(-1) and a capacity retention of 75 % after 190 cycles at 5C.
通过阳极氧化工艺和500°C的热处理获得了从非晶态到锐钛矿结构的自组装二氧化钛纳米管。然后，通过一种电化学工艺成功地在纳米管阵列上沉积了电解磷酸锂薄膜，该工艺包括质子还原，随后pH值升高、磷酸氢盐解离以及磷酸锂在阴极表面沉积。沉积物中的磷酸锂多晶型物（γ或β）可以通过改变电沉积参数（如时间或电流密度）来调整，这由X射线图谱确定。形态分析证明形成了一种三维纳米结构，即磷酸锂包覆二氧化钛纳米管阵列。在锂半电池中测试了阳极 - 固体电解质堆叠。有趣的是，电化学性能表明，对于含少量磷酸锂的样品，其循环稳定性更好，这些磷酸锂是在短时间和低电流密度下沉积的。这些结果表明了制造三维锂离子电池的可能性。纳米管 - 二氧化钛/γ - 磷酸锂/磷酸铁锂全电池在C/5 - 5C范围内以不同速率进行循环。这种受阴极限制的微型电池在5C下190次循环后，可逆重量容量为110 mA h g(-1)，容量保持率为75%。
