Fig. 1

Key research progress in low-temperature lithium batteries in recent years[5-14]"

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[27]; (b) Schematic diagram of the interfacial behaviors and facilitated desolvation in the electrolyte with loose solvation structure[29]; The effect of solvation sheath design on (c) the change of Rct and (d) the intercalation process for graphite anode at low temperature[30]"

Fig. 4

(a) Model of the Li deposition on the surface of graphite anode at low temperature; (b) The relationship between cell voltage and anode potential at various current densities[31]; (c) Schematic diagram of the effects of Li+ transfer and charge transfer on Li deposition behavior at room temperature and low temperature[32]"

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 ℃[35]; (b) Nyquist plot of Li/Li cells with 0.9 mol/L LiPF6 and LiN(CF3SO2)2 respectively[37]; (c) Charge-discharge curves at the 10th cycle of LiNi0.7Co0.1Mn0.2O2/Li cells at -25 ℃[42]; (d) Schematic diagram illustrating the ion transport between electrode and electrolyte in HE electrolyte[43]"

Fig. 6

(a) Melting points and viscosity of commonly used electrolyte solvents[44]; (b) Conductivity of various electrolyte solutions and (c) the discharge curves of Li/Gr half cells at -20 ℃[5]"

Fig. 7

(a) Cyclability of NCM622/Gr cells with different electrolytes at -20 ℃ and C/3 rate[47]; (b) Charge/discharge curves at 0.2C and different temperatures and (c) schematic illustration of the NCM811/Gr cell in the EDFA-FEC electrolyte[48]; (d) Electrostatic potential and ionic conductivities of various electrolytes at 30 ℃, and (e) solvating energies including DEE, BTFE, BDE, TFFE, DFE, and BFE[49]"

Fig. 8

The effects of FEC additive on (a) the first discharge capacity and (b) Tafel polarization[57]; (c) the proposed possible decomposition mechanism of LiDFBOP; The impedance of the Li/Gr cells in the electrolyte (d) without and (e) with LiDFBOP[61]; (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 ℃[73]"

Fig. 9

(a) Cycling performance of NCM811/Gr cells with 3 mol/L LiPF6 EA-FEC electrolyte at -20 ℃ and 0.5C, (b) schematic diagram of the interfacial evolution of graphite anodes[12]; (c) Schematics of the solvation structures and (d) ionic conductivities in commercial dilute electrolyte and HCE at a temperature range of -80—100 ℃[74]; (e) Discharge profiles at different temperatures and (f) cycling performance at -20 ℃ of NCA/Li cells using 1.28 mol/L LiFSI-FEC/FEMC-D2 electrolyte[11]"

Fig. 10

(a) Li+ desolvation activation energy and (b) schematic diagram of the desolvation process in the DME and CPME electrolyte[80]; (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[15]"

Fig. 11

(a) Ligand-channel-facilitated mechanism of Li+ transport behaviors in the FAN electrolyte; (b) Ionic conductivities of liquid and solid-state electrolytes; (c) Cycling performance of 1.2 Ah NMC811/Gr pouch cells with different electrolytes at -50 ℃[14]; (d) The design principle of low-temperature electrolyte"