In this work, we successfully fabricated a carbon fiber-based composite material with a unique vine-like structure using a straightforward electrospinning method that employed dual-carbon-source and a self-catalysis approach. Graphene oxide was incorporated into the spinning matrix, and nickel was used as a catalyst during high-temperature calcination, facilitating the growth of secondary carbon fibers on primary carbon fibers and forming the vine-like structure. This novel hierarchical structure improved the interfacial bonding between carbon fibers, resulting in enhanced conductivity, improved interaction with the electrolyte, reduced lithium-ion diffusion distance, and superior lithium storage performance. The optimized composite material demonstrated excellent lithium storage capabilities, maintaining a specific capacity of 488.5 mAh/g after 400 cycles at a current density of 1 A/g. This work provides a valuable reference for the design of transition metal sulfides with improved lithium storage performance.
The large-scale application of Li-ion batteries requires high-performance cathode materials. Herein, a high-activity Li 3 V 2 (PO 4 ) 3 /C composite cathode has been fabricated through a solid-state reaction employing dual carbon sources of poly(acrylic acid) and soluble starch. The effects of single carbon source and dual carbon sources on the physical and electrochemical properties of Li 3 V 2 (PO 4 ) 3 /C are analyzed. The porous structure induced by poly(acrylic acid) and highly conductive carbon resulted from soluble starch enable the composite to achieve large discharge capacities and stable cyclability at high C-rates. At 3.0–4.3 V and 10 C, a large discharge capacity of 121 mAh g −1 (nearly 91% of the theoretical capacity) can be obtained, along with high capacity retention of 88% over 1000 cycles. Furthermore, at 3.0–4.8 V, the composite also possesses larger high-rate capacities and better cyclability than other composites prepared using single carbon source. The dual carbon sources bring a synergistic effect to the enhancement of electrochemical performances of the Li 3 V 2 (PO 4 ) 3 /C composite.
Nan Zhou,Shengxiong Huang,Tao Hong,Wei Luo,Yun Tian,Xiangyang Lu,Zhi Zhou
In this paper, LiTi 2 (PO 4 ) 3 @carbon composite as anode for aqueous lithium ion battery has been successfully synthesized by in-situ carbon coating method using oxalic acid and glucose as double carbon sources. XRD results confirm the rhombohedral NASICON-type LiTi 2 (PO 4 ) 3 structure of the as-prepared composite. The LiTi 2 (PO 4 ) 3 @carbon composite using double carbon sources (LTP-OG-10) disperses well, and the coated carbon layer has the appropriate thickness of 3–7 nm, which result in proper balance of the good electrical conductivity and the fast kinetics of diffusion of lithium ions . LTP-OG-10 exhibits better electrochemical performance compared with those using oxalic acid (LTP-O) or glucose (LTP-G) single carbon source. LTP-OG-10 anode delivers the discharge capacity of 112.5 mA h g −1 , 96.8 mA h g −1 , and 54.2 mA h g −1 at 0.2 C, 5 C and 20 C, respectively, much larger than that of LTP-O and LTP-G. Moreover, LTP-OG-10 demonstrated excellent cycling performance, with the capacity retention of 71.1% after 400 cycles at 0.2 C, 22.9% higher than that of LTP-G. The good electrochemical properties of LTP-OG-10 is mainly ascribed to the increase of defects, high-quality and appropriate thickness of carbon layer. Our study reveals that preparing LiTi 2 (PO 4 ) 3 @carbon composite using double carbon sources is an efficient approach to enhance its electrochemical properties.
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