The Limits of Low-Temperature Performance of Li-Ion Cells

Abstract

Li-ion batteries are widely used at room temperature because of their high specific energy and energy density, long cycle life, low self-discharge, and long shelf life. 1-3 For certain defense and space applications they are required to be used at low temperatures (<Ϫ30ЊC). In general they exhibit poor low-temperature performance. For example, it has been reported that the capacity of Li-ion cells at Ϫ40ЊC is 12% of the room temperature value. 4 It has been suggested that the poor performance of Li-ion batteries at low temperatures is due to the electrolyte, which determines Li-ion mobility between the electrodes and the transport properties of the passivation film on the carbon anode. 4-8 Most previous studies have focused on the development of low-temperature electrolytes. However, recent preliminary studies by Huang et al. suggest that the primary cause of the poor Li-ion cell performance at low temperature is related to Liion diffusion in the carbon anode and not in the electrolyte or passivating film. 9 It is the purpose of this paper to confirm that the poor Li-ion cell performance at low temperature (<Ϫ30ЊC) is controlled by slow Liion diffusion in the carbon anode and not in the electrolyte or in the passivating film on the carbon anode by evaluating the following at low temperature: (i) electrolytes, (ii) cathode performance, (iii) solid electrolyte interphase (SEI), (iv) anode performance, and (v) effect of the electrode active material particle size. Experimental Electrolyte.-The electrolytes evaluated in this study were chosen because of previous low-temperature Li-ion battery studies of the Jet Propulsion Laboratory (JPL). 10 Four carbonate-based solvent electrolytes were tested: (i) 1.0 M LiPF 6 ethylene carbonate (EC):diethyl carbonate (DEC):dimethyl carbonate (DMC) (1:1:1 vol %); (ii) 0.9 M LiPF 6 EC:DEC:DMC:propylene carbonate (PC) (3:3:3:1); (iii) 0.8 M LiPF 6 EC:DEC:DMC:ethyl methyl carbonate (EMC) (3:5:4:1), and (iv) 0.8 M LiPF 6 EC:DEC:DMC:EMC (3:5:4:2). The electrolytes, purchased from Mitsubishi Chemical Company, were sealed in glass tubes in a glove box. The samples were put into a low-temperature chamber, and the temperature was lowered first to Ϫ20, then to Ϫ30, Ϫ35, Ϫ40, and finally to Ϫ42.5ЊC. The samples were kept at each temperature for 4 days. The electrolyte liquidus range at low temperatures was evaluated through visual inspection. In the case of 1.0 M LiPF 6 EC:DEC:DMC (1:1:1), the solid phase that formed at Ϫ35ЊC was separated and analyzed using a gas chromatograph coupled with a mass spectrometer.Electrode.-The electrode materials investigated were: mesocarbon microbead (MCMB) graphite, coke, and LiCo 0.2 Ni 0.8 O 2 . MCMB graphite and coke were chosen because of their potential as anodes in Li-ion batteries as a result of their high specific capacity and long cycle life. LiCo 0.2 Ni 0.8 O 2 was investigated because of its potential as a cathode in Li-ion batteries as a result of its relatively high specific capacity and more importantly, its high Li diffusion coefficient.To ev...

Radially aligned hierarchical columnar structure as a cathode material for high energy density sodium-ion batteries

“…The delivered capacities of the cell reached 143 mAh g À 1 at 30°C, 147.6 mAh g À 1 at 55°C and 128.8 mAh g À 1 at 0°C. The capacity decreases to 114 mAh g À 1 at À 20°C; however, this value is still sufficiently high compared with Li cells [45][46][47] . At 30°C, the average operation voltage is found to be 2.84 V on discharge.…”

A critical review of thermal management models and solutions of lithium-ion batteries for the development of pure electric vehicles

“…Huang et al [80] and Lin et al [76] pointed out that a lithium-ion battery might be able to be discharged normally at low temperatures, but not so during reverse charging process. Nagasubramanian [81] reported that the commercial 18650 lithium-ion battery has only 5% of energy density and 1.25% of power density compared to that obtained at 20°C.…”

“…Poor lithium-ion battery performance under cold climates is therefore studied [84,86,87] which can be summarised from four factors: 1) low conductivity of the electrolyte and solid electrolyte interface on the electrode surface [88,89]; 2) declined solid-state Li diffusivity [80,84]; 3) high polarisation of the graphite anode [76,90]; and 4) the sluggish kinetics and transport processes caused by increased charge-transfer resistance on the electrolyte-electrode interfaces [80,84]. Three contributing factors of a PHEV lithium-ion battery impact of low ambient temperature at -7°C and 0°C have been quantified [82].…”

Towards an Ultimate Battery Thermal Management System: A Review

“…Although the capacity increases as the operating temperature is raised, the degree of capacity fade also increases. On the other hand, poor performance is observed at low operating temperature [12,13]. In addition, excessive or uneven temperature rise in a system or pack reduces its lifecycle significantly [14].…”