What do you think of micro-macro's non-burning battery technology?

The micro-macro's non-burning battery mainly changes the defects of the lithium battery from the three core technologies of non-burning electrolyte, high-temperature lithium ion separator and thermal control fluid technology, which can avoid the burning of lithium ion battery.

One attempt at high safety is to use lithium titanate (Li4Ti5O12, abbreviated as LTO) as the negative electrode. When the LTO is completely discharged, it will become an insulator and enjoy a good reputation for safety. According to Toshiba's report, LTO did not experience thermal runaway at a high temperature of 300 ° C, and the cycle characteristics, load characteristics, and charge acceptance performance were good.

But LTO also has short boards. The average voltage of the LIB using the LTO negative electrode is only 2.4 to 2.5 V, and the number of battery packs is increased to 1.5 times, so that the voltage can be flush with the usual LIB. Moreover, the energy density of this LIB is low. For LTO with a low voltage, if the current carrying density does not increase, the energy density will not increase. Toshiba, which developed the LTO negative electrode, said that the effective discharge capacity of LTO is about 160 mAh·g-1 (Fig. 2). The theoretical effective discharge capacity of graphite (C) is about 350mAh·g -1 (theoretical value is 372mAh·g -1). Compared with this, the discharge capacity of LTO is significantly lower.

Toshiba's data shows that the effective discharge capacity of LTO is only 160mAh·g-1. (Assuming that all of the lithium in Li[LTO] participates in the discharge reaction, the obtained discharge capacity of LTO is 175 mAh·g-1, which is the case when the lithium utilization rate is about 91%.)

The density data of LTO is used to calculate the volumetric energy density of LTO, but the relevant data is not disclosed. The approximate unit volume discharge capacity was estimated using the density of Li2TiO3 (4.3g·cm -3 ), and the result was 544mAh·cm -3 . For graphite, the value obtained from the above-mentioned effective discharge capacity and density (2.25g·cm -3 ) was about 790mAh·g -1 . It can be seen that LTO is also inferior to graphite in unit volume discharge capacity.

Note: Li2TiO3 has three crystal forms, namely anatase, brookite and rutile. The densities were 3.9, 4.0, and 4.3g·cm -3, respectively. Here, in order to simplify the calculation, the density of the rutile type having the most stable heat state is 4.3 g·cm-3.

These data show that the disadvantage of LTO in energy density is very obvious. But LTO is not all bad, its advantages include discharge curve almost straight, very good control. Moreover, LTO is more positive relative to lithium, which means that even if the discharge depth (SOC) reaches 100%, lithium metal will not be precipitated. This means it is also extremely safe when overcharged.

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