A single-ion gel polymer electrolyte system for improving cycle performance of LiMn2O4 battery at elevated temperatures

Abstract

a b s t r a c tThe LiMn 2 O 4 based lithium batteries using commercially available electrolytes suffer from poor cycling performance at elevated temperatures (above 55• C). This is mainly caused by the Mn dissolution generated from HF thermally decomposed from the LiPF 6 salt at elevated temperatures. In this paper, a single-ion gel polymer electrolyte (polymeric lithium tartaric acid borate @ poly(vinylidene fluoride-cohexafluoropropylene) was explored for improving the cycling performance of the LiMn 2 O 4 based lithium battery at elevated temperatures owing to superior thermal stability and comparable ionic conductivity. It was manifested that the Li/LiMn 2 O 4 cells using this single-ion gel polymer electrolyte showed stable charge/discharge voltage profiles, preferable rate capability and excellent cycling performance both at room temperature and elevated temperature of 55• C. The dissolution of metallic Mn in this electrolyte is significantly suppressed than that of LiPF 6 electrolyte. These superior performances could endow this single-ion gel polymer electrolyte a promising alternative to the conventional liquid electrolyte system in the LiMn 2 O 4 battery at elevated temperatures.

Gel Polymer Electrolytes for Electrochemical Energy Storage

“…[63] For example, the lithium tartaric acid borate (PLTB)-based single lithium-ion conducting GPEs were demonstrated to improve the cyclic performances of LiMn 2 O 4 /Li cell and obviously alleviate the generation of lithium dendrites on Li anodes, compared with LiPF 6 -based electrolyte at elevated temperature of 55 °C. [68] Similarly, the ionic conductivity is also critical for the practical application of single lithium-ion conducting GPEs, which are governed by the ionic mobility in polymer hosts. To this end, a promising approach to increase the Li + ion mobility in gel polymer is to enhance the segmental motion of the polymer backbone by lowering their T g or introducing polymer backbones with low T g than that of the room temperature.…”

A new composite solid electrolyte PEO/Li10GeP2S12/SN for all-solid-state lithium battery

“…Furthermore, during the charging and discharging, it takes a few cycles to facilitate Li + ion pathways between the electrolyte and electrode as well [53]. Certainly, there has been reported that it needs the activation process to activate electrodes [54][55][56]. So it may well be that these coefficient reasons described above give rise to the activation process.…”

Composite membrane with ultra-thin ion exchangeable functional layer: a new separator choice for manganese-based cathode material in lithium ion batteries

“…As shown in Fig. 2c, the PP separator, Naon membrane and the Nf-PP-Li separator all have high thermal decomposition temperatures over 300 C. 19 So the Nf-PP-Li separator exhibited better thermal stability. According to the DSC curves shown in Fig.…”

“…The ion conductivity of the PP substrate at room temperature is 4.98 Â 10 À4 S cm À1 . Since a high lithium ion transference number has long been pursued, 19 preparation or introduction of the -SO 3 Li groups has proved to be an effective method and is expected to alleviate ion concentration gradients, decreasing internal resistance and alleviating interface polarization within lithium ion batteries. the bulk resistance of the Naon based material is much higher, as shown in Fig.…”

“…Among these challenges, the Mn dissolution is a critical issue, which usually results in rapid capacity loss, especially when the batteries are deposited at high temperature. 5,18,19 Nevertheless, the limitations of these kinds of gel polymer electrolytes lie in that they are difficult to be scaled up and their high cost. HF is usually formed by the reaction of the LiPF 6 with the residual moisture in the electrolyte and the thermal decomposition of the LiPF 6 .…”