An international team from Hanyang University (Korea), University of Rome “La Sapienza” (Italy), and Argonne National Laboratory (US) has synthesized a cathode material of an electrically conducting carbon-LiMnPO4 nanocomposite by ultrasonic spray pyrolysis followed by ball milling. They then examined the effect of the carbon content on the physicochemical and electrochemical properties of the material.
An LiMnPO4 electrode with 30 wt% acetylene black (AB) carbon exhibits an excellent rate capability and good cycle life in cell tests at 55 and 25 °C. This electrode delivers a discharge capacity of 158 mAh g-1 at 1/20 C, 126 mAh g-1 at 1 C, and 107 mAh g-1 at 2 C rate, which are the highest capacities reported so far for this type of electrode, the team reported in a paper published in the journal Advanced Functional Materials.
Transmission electron microscopy and Mn dissolution results confirm that the carbon particles surrounding the LiMnPO4 protect the electrode from HF attack, leading to a reduction of the Mn dissolution that usually occurs with this electrode. The improved electrochemical properties of the C-LiMnPO4 electrode were also verified by electrochemical impedance spectroscopy.
Seung-Min Oh, Sung-Woo Oh, Chong-Seung Yoon, Bruno Scrosati, Khalil Amine, Yang-Kook Sun (2010) High-Performance Carbon-LiMnPO4 Nanocomposite Cathode for Lithium Batteries. Advanced Functional Materials doi: 10.1002/adfm.201000469