Advanced LiTi2(PO4)3 anode with high performance for aqueous rechargeable lithium battery

Abstract In this work, a high-performance LiTi2(PO4)3 coated with N-doped carbon was prepared throught sol-gel method followed by high-temperature carbonization using polyacrylonitrile (PAN) as both carbon and nitrogen sources. The morphology, structure, and electrochemical properties of LiTi2(PO4)3 samples with various carbon content are investigated. LiTi2(PO4)3 composite with 5.9% carbon exhibits the best electrochemical properties due to good dispersion, proper thickness of carbon layer, nitrogen doping for carbon layer. When tested as anode for aqueous rechargeable lithium battery, LiTi2(PO4)3 with 5.9% carbon demonstrates outstanding rate and cycling performance. The composite delivers the discharge capacity of 120.0, 106.9, and 79.1 mAh g−1 at 1, 5, and 20 C, respectively, and the capacity retention can reach 86.4% after 1000 cycles at 5 C. The excellent properties of as-synthesized sample mainly come from the accelerated transfer of lithium ions and electrons due to formation of more nano-scale channel and nitrogen doping for carbon layer. Our study reveals that PAN shows a promising prospect as both carbon and nitrogen sources in synthesis of LiTi2(PO4)3-based electrode.