N-doped carbon microspheres anode from expired vitamin B1 injections for lithium ion battery.

The treatment of expired medical injections has always been a thorny environmental concern due to high liquid mobility and crispy glass bottle package. For this purpose, in this work, expired vitamin B₁ (VB₁) injections were recycled via the hydrothermal carbonization pelletizing and the following pyrolysis for the first time. The resultant VB₁-derived N-doped carbon (VBNC) appeared as the morphology of regular micro-spheres with the mean diameter of 3.4 ± 0.7 μm. Furthermore, as the anode-active material in lithium ion battery (LIB), it also delivered high initial discharge capacity of 731 mAh g⁻¹ at 0.025 A g⁻¹ and the reversible discharge capacities of 358, 292, 203 and 118 mAh g⁻¹ even at 0.5 A g⁻¹, 1 A g⁻¹, 2 A g⁻¹ and 4 A g⁻¹ for 500 cycles. Regular micro-spherical morphology and N-doping effect may jointly contribute into the satisfactory electrochemical performances, indicating high feasibility for LIB anode and offering a good strategy to recycle expired waste VB₁ injections. [ABSTRACT FROM AUTHOR]