Fig. 1

Key research progress in low-temperature lithium batteries in recent years"

Fig. 2

Key issues limiting the electrochemical performance of low-temperature LIBs"

Fig. 3

（a） Schematic description of energetic coordinates for “Li+ transfer” at graphite/electrolyte junction. （b） Schematic diagram of the interfacial behaviors and facilitated desolvation in the electrolyte with loose solvation structure. （c） The effect of solvation sheath design on （c） the change of Rct and （d） the intercalation process for graphite anode with temperature decrease"

Fig. 4

（a） Model of the Li deposition on the surface of graphite anode at low temperatures， （b） The relationship between cell voltage and anode potential at various current densities. （c） Schematic diagram of the effects of Li+ transfer and charge transfer on Li deposition behavior at room and low temperature"

Table 1

Characteristics of commonly used lithium salts in LIBs"

Fig. 5

（a） Ionic conductivities of electrolytes with various Li salts in different carbonate-based solvents at -40~+60 °C. （b） Nyquist plot of Li/Li cells with 0.9 M LiPF6 and LiN（CF3SO2 ） 2， respectively. （c） Charge-discharge curves at the 10th cycle of LiNi0.7Co0.1Mn0.2O2/Li cells at -25 °C. （d） Schematic diagram illustrating the ion transport between electrode and electrolyte in HE electrolyte"

Fig. 6

（a） Melting points and viscosity of commonly used electrolyte solvents. （b） Conductivity of various electrolyte solutions and （c） the discharge curves of Li/Gr half cells at -20 °C"

Fig. 7

（a） Cyclability of NCM622/Gr cells at C/3 rate with different electrolytes at -20 °C. （b） Charge/discharge curves of NCM811/Gr cells at 0.2 C and different temperatures and （c） schematic illustration of the NCM811||Gr cell in the EDFA-FEC electrolyte. （d） Electrostatic Potential and ionic conductivities of various electrolytes at 30 °C， and （e） solvating energies including DEE， BTFE， BDE， TFFE， DFE， and BFE"

Fig. 8

The effects of FEC additive on （a） the first discharge capacity and （b） Tafel polarization. （c） the proposed possible decomposition mechanism of LiDFBOP， the impedance of the Li/Gr cells in the electrolyte （d） without and （e） with LiDFBOP. （f） The working mechanism of TMSP and PCS functional additives and （g） the corresponding cycling performance of LNMO/MCMB full cells at 0.3C and -5 °C"

Fig. 9

（a） Cyclic performance of NCM811/Gr cells with 3 M LiPF6 EA-FEC electrolyte at -20 oC and 0.5C， （b） schematic diagram of the interfacial evolution of graphite anodes. （c） Schematics of the solvation structures and （d） ionic conductivities in commercial dilute electrolyte and HCE at a temperature range of -80~+100 °C. （e） Discharge profiles at different temperatures and （f） cycling performance at -20 °C of NCA/Li cells using 1.28 M LiFSI-FEC/FEMC–D2 electrolyte"

Fig. 10

（a） Li+ desolvation activation energy and （b） schematic diagram of the desolvation process in the DME and CPME electrolyte. （c） Ionic conductivity of the investigated electrolytes， （d） discharge profiles of LCO/Gr cells at different temperature， （e） relationship of solvation structure and physical properties of electrolyte"

Fig. 11

（a） Ligand-channel-facilitated mechanism of Li+ transport behaviors in the FAN electrolyte， （b） ionic conductivities of liquid and solid-state electrolytes from 60?°C to -70?°C， （c） cycling performance of NMC811/Gr pouch cells with different electrolytes at -50?°C. （d） The design principle of low-temperature electrolyte"