In recent years, small and convenient electronic devices have developed rapidly, while large and rigid energy equipment cannot meet the requirements of these devices. In order to match these micro devices, energy devices are developing towards micro ones. Compared with the flat sandwich battery, the linear fiber lithium ion battery has the flexible characteristic. Fibre-lithium ion batteries are small, adaptable and braided, but the preparation of suitable fibre-lithium ion electrodes requires advanced technology.
TiO2/ rGO fiber synthesis flow chart
Researchers from geng fengxia research group of suzhou university processed TiO2 into nano-sheets and synthesized nano-fibers through wet spinning technology. TiO2 nano-sheets and reduced graphene (rGO) were deposited and co-precipitated to form a highly efficient collector fluid. Meanwhile, TiO2/rGO fiber electrode has ultra-high mechanical strength and excellent electrochemical properties.
(a) schematic diagram of a semi-cell (b) voltage capacity diagram (c) multiplier diagram (c) long cycle
TiO2/ rGO fiber electrode lithium metal wire was assembled into a semi-battery, and the electrochemical properties were tested under the condition of 1-3v potential window. The length of the fiber battery is 3cm, and it is charged and discharged at the current of 0.0085mA. The initial discharge specific capacity is up to 168mAh/g (theoretical specific capacity is 170mAh/g). At the current of 0.0085, 0.0170, 0.0255, 0.0340 and 0.0425mA, the capacitance is maintained at 89mAh/g at the maximum current of 0.0425mA, and at 150mAh/g when the current returns to 0.0085mA. When the current of the battery is 0.0170ma, the initial discharge specific capacity is 126mAh/g. After 100 cycles, the capacity is maintained at 100mAh/g, and the capacity retention rate is up to 80%.
Flexible all-battery performance chart (a) when one LED light battery work more than 5h(b) when the battery bending voltage (c) 30cm battery can make 6 LED lights work.
LiMn2O4 is a full battery assembled with TiO2/rGO for the positive electrode. A 10cm hybrid fibre battery can supply an LED (2V, 60mW) for more than 5 hours continuously. TiO2/rGO nano-fiber synthesized by TiO2 nano-sheet shows such good electrochemical properties, which proves the rationality and feasibility of material design, which is of great significance for advanced flexible battery energy storage materials.