Structure and Low‐temperature Performance of Waste Graphite Used in Lithium‐ion Battery Anode

Abstract

Graphite is a very important mineral resource and strategic resource. With the continuous decrease of graphite resources consumption, the recycling of graphite is getting more and more attention. In this work, lithium‐ion battery anode materials were prepared from discarded high‐purity graphite crucibles by crushing, shaping, purification and coating processes, and structural and electrochemical properties of materials were investigated, as well as the low‐temperature charging and discharging performance.The results show that, the initial discharge capacity of TCH sample is 419.4 mAh/g, and the initial coulombic efficiency is 80.4 %. The initial coulombic efficiency reached 88.1 % and the capacity is 345.9 mAh/g after 100 cycles, when the coating amount was 10 wt%. The initial coulombic efficiency, polarization and low temperature properties of carbon coating materials are obviously improved.First‐principles calculations reveal that the reason for the improvement of electrochemical performanceduetothe coating reduces the Li‐ion diffusion barrier.

Boosting the Low-Temperature Performance of Graphite Anodes by Creating an Electrochemically Active Interface

“…Figure 4b presents the capacity retention and reversible capacity for recent advances in graphite surface modification, including our LBL-modified graphite during low-temperature operation (0.1C and −20 °C if not indicated otherwise in the figure). In comparison to SEI structures improved by electrolyte modification, 12,[19][20][21]43 our LBL-modified graphite demonstrates superior performance with higher reversible capacity and capacity retention for low-temperature conditions (Figure 4b). Furthermore, the longtime cycling of LBLmodified graphite shows a capacity retention of ∼70.7% after 100 cycles at −20 °C (0.1C), which is competitive with those SEI-modified graphite anodes.…”