Preparation of nanorod-assembled CNT-embedded LiMnPO₄ hollow microspheres for enhanced electrochemical performance of lithium-ion batteries

Abstract

LiMnPO4 is a promising cathode material for lithium-ion batteries, but it has the drawback of poor electronic conductivity and low Li+ diffusivity. Here, we expect to simultaneously improve electron transfer...

LiMn0.8Fe0.2PO4@C cathode prepared via a novel hydrated MnHPO4 intermediate for high performance lithium-ion batteries

“…This indicates that addition of an adequate amount of oxalic acid makes a great contribution to improving the electrical conductivity of the LiMn 0.8 Fe 0.2 PO 4 @C cathode, reducing the resistance of the charge transfer at the interface of electrolyte and electrode, facilitating Li + diffusion, and improving the ionic conductivity. In addition, the exchange current density (i 0 ) was used to illustrate the electrochemical activity of the electrodes, and was calculated according to eqn (9), as shown in Table S3. † 51…”

“…74-0375). 9 Table S1† shows the lattice parameters and cell volume of samples calculated from the refinement of the XRD patterns. As can be seen, the lattice parameters a , b , and c , and cell volume V remain nearly the same for the pristine sample LMFP-0 and when oxalic acid was added.…”

“…7,8 However, LiMnPO 4 has a low electrical conductivity (<10 −10 S cm −1 ) and poor Li + intercalation/deintercalation kinetics compared with other cathode materials, resulting in a low ionic/electronic dynamic ability. 9,10 Furthermore, an inherent obstacle for LiMnPO 4 is the Jahn-Teller effect caused by the structural distortion of Mn 3+ during the lithiation of the Mn-rich phase. 11,12 To overcome these shortcomings, considerable progress has been made in improving the electrochemical performance of LiMnPO 4 , such as carbon coating, reducing grain size, and heterogeneous metal cation doping (e.g.…”

“…7,8 However, LiMnPO 4 has a low electrical conductivity (<10 −10 S cm −1 ) and poor Li + intercalation/deintercalation kinetics compared with other cathode materials, resulting in a low ionic/electronic dynamic ability. 9,10 Furthermore, an inherent obstacle for LiMnPO 4 is the Jahn–Teller effect caused by the structural distortion of Mn 3+ during the lithiation of the Mn-rich phase. 11,12…”

Boron‐Catalyzed Graphitization Carbon Layer Enabling LiMn0.8Fe0.2PO4 Cathode Superior Kinetics and Li‐Storage Properties

“…[ 3 ] However, the pure phase LiMnPO 4 exhibits poor electrical conductivity (10 −10 S cm −1 ) and slow ion diffusion coefficient (10 −18 cm 2 s −1 ) through the interface between LiMnPO 4 and MnPO 4 , these drawbacks inhibit its application. [ 4 ] In recent years, the most common modification method is to substitute part of Mn with Fe, which not only effectively improves the bulk conductivity, but also suppresses the Jahn‐Teller distortion caused by Mn 3+ to some extent. [ 5 ] Therefore, the generation of stable solid solution LiMn 1‐x Fe x PO 4 with the advantages of LiMnPO 4 (high working voltage) and LiFePO 4 (long cycle life) has attracted extensive attention.…”