Safety lithium metal secondary batterie

Secondary lithium-metal batteries which have a lithium-metal anode are attractive because their energy density is theoretically higher than that of lithium-ion batteries. Lithium-molybdenum disulfide batteries were the world s first secondary cylindrical lithium—metal batteries. However, the batteries were recalled in 1989 because of an overheating defect. Lithium-manganese dioxide batteries are the only secondary cylindrical lithium—metal batteries which are manufactured at present. Lithium-vanadium oxide batteries are being researched and developed. Furthermore, electrolytes, electrolyte additives and lithium surface treatments are being studied to improve safety and recharge-ability. 

One of the most important factors determining whether or not secondary lithium metal batteries become commercially viable is battery safety, which is affected many factors insufficient information is available about safety of practical secondary lithium metal batteries [91]. Vanadium compounds dissolve electrochemi-cally and are deposited on the lithium anode during charge-discharge cycle. The... 

To improve the safety of secondary lithium batteries, the metallic lithium is replaced by another intercalation compound such as graphite. In addition, the cathode would contain ionic lithium in its structure, which is intercalated in the anode or the cathode depending on the direction of the current. Lithium-ion cells are the most advanced batteries now in the market. These cells supply up to 4 volts, have an energy density close to 120 Wh/kg, and have a long life at room temperature. The technology is based on the use of appropriate lithium intercalation compounds as electrodes. Normally a lithium transition metal oxide is used as the cathode and carbonaceous materials serve as the anode. 

Rechargeable lithium batteries have been introduced into the market on a limited scale. Coin cells, using lithium-aluminum anodes, are available for special applications mainly for low-power portable applications where they can be conveniently recharged, in some instances by solar cells. A small cylindrical cell, using a lithium anode, was briefly, and perhaps prematurely, introduced in the 1980s for consumer electronics applications, but was withdrawn when safety problems arose. More recently, the lithium-ion cell, which has a safety advantage over other lithium secondary cells as it does not contain lithium in a metallic form, has been marketed as a power source for consumer electronics such as cellular phones and camcorders. This technology has become dominant in the market. 

Most recent secondary lithium batteries use carbon as its anode, replacing metallic lithium found in primary batteries. Carbon anode provides greater cell life with safety and low cost however, it also has lower cell voltage, rate capability, and specific charge (theoretical capacity of 372 mA h g ). For the improvement of these specific properties, scientists have studied various nanofibrous anode materials with improved performance with respect to the above parameters. A comparison of specific capacities of various modified and unmodified carbon nanofiber (CNF) anodes is presented in Fig. 3.3. Kim et al. prepared CNFs by combining electrospinning and thermal treatments. Due to the particular nanotexture, these polyacrylonitrile... 

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