Long-lived Aqueous Rechargeable Lithium Batteries Using Mesoporous LiTi2(PO4)3@C Anode

Abstract

The instability of anode materials during cycling has been greatly limiting the lifetime of aqueous rechargeable lithium batteries (ARLBs). Here, to tackle this issue, mesoporous LiTi2(PO4)3@C composites with a pore size of 4 nm and a large BET surface area of 165 m2 g−1 have been synthesized by a novel two-step approach. The ARLB with this type of LiTi2(PO4)3@C anode, commercial LiMn2O4 cathode and 2 M Li2(SO4) aqueous solution (oxygen was removed) exhibited superior cycling stability (a capacity retention of 88.9% after 1200 cycles at 150 mA g−1 and 82.7% over 5500 cycles at 750 mA g−1) and excellent rate capability (discharge capacities of 121, 110, 90, and 80 mAh g−1 based on the mass of LiTi2(PO4)3 at 30, 150, 1500, and 3000 mA g−1, respectively). As verified, the mesoporous structure, large surface area and high-quality carbon coating layer of the LiTi2(PO4)3@C composite contribute to the breakthrough in achieving excellent electrochemical properties for ARLB.

Opportunities and Challenges for Organic Electrodes in Electrochemical Energy Storage

“…Interestingly, such volumetric capacities are actually lower than that obtained for a quinone derivative also used on the negative side, the poly pyrene-4,5,9,10-tetraone (PPTO): 1.68 g cm –3 , 338 mAh cm –3 , 201 mAh g –1 cycled in Na + -based aqueous electrolyte . Although the PPTO electrode contained 30 wt.% of carbon additive its electrode volumetric capacity (144 mAh cm –3 ) remains in the vicinity of that derived for the titanium phosphate ones: 121 mAh cm –3 , ref and 152 mAh cm –3 , ref . It is also important to point out that the previous results were obtained from relatively thin electrodes with areal capacity in the vicinity or below 1 mAh cm –2 .…”

“…On paper, this is not one of the most important factors for stationary energy storage although in practice, low energy density could also mean more layers in the stack (for a given electrode thickness) and therefore a higher price due to a larger amount of passive elements. The volumetric capacity of the C@Na­(Li)­Ti 2 (PO 4 ) 3 (2.6 g/cm 3 ) can reach up to 231–300 mAh cm –3 (93–118 mAh g –1 , respectively) taking into account the carbon coating (2.0 g·cm –3 ). Interestingly, such volumetric capacities are actually lower than that obtained for a quinone derivative also used on the negative side, the poly pyrene-4,5,9,10-tetraone (PPTO): 1.68 g cm –3 , 338 mAh cm –3 , 201 mAh g –1 cycled in Na + -based aqueous electrolyte .…”

NASICON-Type Mg0.5Ti2(PO4)3 Negative Electrode Material Exhibits Different Electrochemical Energy Storage Mechanisms in Na-Ion and Li-Ion Batteries

“…Most of the studied A x M y (PO 4 ) 3 are alkaline metal-based, such as A 3 V 2 (PO 4 ) 3 and ATi 2 (PO 4 ) 3 , (A = Li, Na). Of these materials, A 3 V 2 (PO 4 ) 3 is considered a promising positive electrode for LIBs and SIBs because of its large specific capacity and excellent rate capability, − and ATi 2 (PO 4 ) 3 is usually considered as a negative electrode because of its low working voltage vs Li + /Li and Na + /Na. − …”

Evaluation of the Stability of Carbon Conductor in the Cathode of Aqueous Rechargeable Lithium Batteries against Overcharging

“…LiMn 2 O 4 is a very common Li-ion intercalation-type cathode for both aqueous and non-aqueous batteries [1][2][3][4][5]. The aqueous rechargeable LiMn 2 O 4 battery has been developed extensively with different types of anodes [6][7][8][9][10][11][12][13][14][15][16]. Considering cost, operational safety, and environmental issues, aqueous rechargeable lithium batteries (ARLBs) are more attractive than their non-aqueous analogues [6].…”

“…Moreover, the ionic conductivity of typical aqueous electrolytes is about two orders of magnitude higher than those of non-aqueous analogues, leading to better rate capability of the aqueous-based battery [6]. In addition to the development of ARLBs conducted by several research groups [7,[9][10][11][12][13][14][15][16]], Chen's group has introduced the rechargeable hybrid aqueous battery (ReHAB), which combines an intercalation cathode (LiMn 2 O 4 , LiFePO 4 ) with a metal (first order electrode such as zinc) anode and an aqueous electrolyte containing both Li + and Zn 2+ [17][18][19][20][21][22].…”