Oxygen vacancy modulated Ti2Nb10O29-x embedded onto porous bacterial cellulose carbon for highly efficient lithium ion storage

Rational design & modulation of ion/electron transfer paths are critical for achieving high-performance anode materials for lithium ion batteries . In this work, we first time realize smart assembly of oxygen vacancy modulated titanium niobium oxide (Ti 2 Nb 10 O 29-x , TNO x ) onto highly conductive bacterial cellulose carbon (BCC) forming BCC/TNO x electrode through a facile solvothermal-annealing method. BCC consists of interlinked (N, S & P) co-doped carbon fibres uniformly decorated with TNO x nanoparticles . Impressively, the introduction of oxygen vacancy can effectively enhance the internal ion/electron transfer in TNO x and enhancement effect is elaborated by synchrotron radiation technology (XANES and XAFS) and DFT calculation. Meanwhile, with the aid of conductive BCC skeleton, the external ion/electron transfer path on TNO x is also greatly improved leading to better reaction kinetics. The synergistic dual internal plus external modulation on transfer path show positive advantages including smaller band gap with better electrical conductivity , and larger lattice parameters with faster ion/electron transfer. Accordingly, the BCC/TNO x electrode is endowed with outstanding lithium ion storage performance with high-rate capability (281 mA h g −1 at 5 C, and 160.5 mA h g −1 at 40 C). Our finding provides valuable insights into design of other advanced electrodes via dual transfer path modulation strategy.