## 1 Introduction  
With the excessive consumption of resources and the deterioration of the environment, it is extremely important to explore new technologies that are efficient, non-toxic, environmentally friendly and reproducible as well as new technologies for storing and transporting energy [1; 2; 3]. Because of their virtues of high energy density, good cycling stability, light-weight, no memory effect, high working voltage and a long service life, lithium ion batteries (LIBs) are considered as one of the most competitive forms of energy stockpile equipment, and LIBs have already been under research focus due to their wide uses in portable electronics, electric vehicles (EVs) and hybrid electric vehicles (HEVs) in the past few decades [4; 5; 6; 7; 8; 9]. As we all know, anode and cathode play decisive roles in the property of LIBs. Among all anode materials, graphite anode has been widely used in commercial lithium ion batteries for decades. However, graphite can no longer satisfy the need for high energy density and power density in new generation of electric vehicles and other electric devices because of its inherent lower theory capacity (372 mAh g\({}^{-1}\)) [10; 11; 12; 13]. It is well known that carbon is an indispensable element to our carbon based life and it's extensively distributed in atmosphere, the Earth's crust and carbon-based life by elemental carbon (graphite, diamond) and combined carbon (carbonates, oxycarbide and organics). It is generally accepted that our ancestors began to understand and take advantage of the earth's carbon thousand years ago [14]. With the development of new technologies, carbonaceous materials were extensively used among energy storage, electronic devices, catalytic, adsorption and other domains over recent decades [15; 16; 17; 18]. Due to carbon's abundance, low cost and friendly environment, a variety of carbon anode were adopted to enhance the electrochemical properties of carbonaceous materials and overcome the disadvantage of graphite anode materials in LIBs. One acceptable option is to design carbon into nanosize with various morphologies, including zero-dimensional [19; 20], one-dimensional [21; 22; 23; 24; 25; 26], two-dimensional [27; 28; 29; 30; 31] and three-dimensional carbonaceous materials [32; 33; 34; 35], in which nanostructure materials can improve the electrochemical property by shorten the transmission way of lithium ions and electrons. In addition, heteroatom(s) doped carbonaceous materials have been studied [36; 37; 38; 39; 40; 41], which show that doping of heteroatom(s) can cause defects, increase extra valid available active sites, and improve the electronic and chemical characteristics, resulting in the enhancement of electrochemical performance in LIBs. Nevertheless, it is a serious challenge to obtain high performance fungible anodes which are simultaneously endowed with no toxic, low cost, high capacities, outstanding rate capability and excellent cycle stability via a convenient and controllable method for lithium ion batteries. In this work, a porous carbon nanofiber film (PCNF) electrode has been prepared using aqueous polyvinylpyrrolidone (PVP) solution by a simple and inexpensive electrospinning method and the following carbonization and air etching process. The as-prepared PCNF film have been directly used as an anode for lithium ion battery with no additional binder and conductive addictive, and even no extra metal current collector. The stable self-supporting conductive film electrodes and the unique porous features in each carbon nanofiber will help to promote the transportation of Li-ion and electron and relieve the large volume dilation while inserting the lithium ion. As expected, the obtained PCNF electrode sample demonstrates a high reversible capacity of 1138 mAh g\({}^{-1}\) at C-rate of 0.1 C and superior cycling durability with a capacity decay rate of \(\sim\)0.013% per cycle upon 1000 cycles.