High capacity and rate capability of a layered Li₂RuO₃cathode utilized in hybrid Na⁺/Li⁺batteries

Abstract

A novel hybrid Na + /Li + battery is established by using Li 2 RuO 3 as the cathode, 1 M NaClO 4 in 1 : 1 EC/PC solution as the electrolyte and metallic sodium as the anode. In the working voltages between 2.0 and 4.0 V, Li 2 RuO 3 delivers a high discharge capacity of 168 mA h g À1 under the current density of 0.1 A g À1 and an excellent capacity retention of about 88.1% after 50 cycles. The cathode also exhibits superior rate capability and long-term cycle life, whose discharge capacity reaches 85 mA h g À1 after 300 cycles at the current density of 1 A g À1 . Importantly, both Na + and Li + can reversibly intercalate/deintercalate into Li 2 RuO 3 in the same manner as in the typical Li-ion half cell. In addition, ex situ X-ray diffraction patterns of the initial charge and discharge processes as well as after long electrochemical cycles are examined to study its structural evolution. Our studies provide a strong insight into the design and application of novel rechargeable batteries.

Exploration of Spinel LiCrTiO4 as Cathode Material for Rechargeable Mg‐Li Hybrid Batteries

“…To further obtain direct insight into the ion‐transport behavior of LiCrTiO 4 in the Mg‐Li hybrid system, ex situ EDX measurements were carried out in the initial cycle and after 30 cycles. It should be noted that it is difficult to detect the content of Li + ions through EDX measurement due to its detection limit . After normalization with respect to the content of Ti 4+ ions, a small amount of Mg 2+ ions could be detected, as indicated in Table .…”

Defect Chemistry and Li-ion Diffusion in Li2RuO3

“…24 studied the electrochemical properties of Li 2 RuO 3 and concluded that there are two working plateaus in the first charging process providing a reversible capacity of approximately 270 mAhg −1 . A novel hybrid Na + /Li + battery has been recently made using Li 2 RuO 3 as a cathode material because of its unique structure accommodating both Li + and Na + ions 27 . Li 2 RuO 3 was suggested as an additive to provide high energy lithium-ion capacitors due to its high reversible characteristics for Li + ion intercalation/de-intercalation and structural stability 28 .…”

Multiscale Investigation into the Co‐Doping Strategy on the Electrochemical Properties of Li2RuO3 Cathodes for Li‐Ion Batteries

“…The experimental value of the electrical conductivity coefficient for the LRO cathode is 18 (S m −1 ) [23] . For the other cathodes, the electrical conductivity coefficient for the P1D model has been calculated from Equation 17, and summarized in Table 5.…”

“…One of the main groups of these kinds of cathode materials is Lithium‐rich layered Ru‐based oxides (LRO). However, LROs also have drawbacks such as oxygen loss, poor electrochemical kinetics, low Li‐ion diffusion coefficient, and large voltage reduction, that need to be mitigated [22–25] . For example, the diffusion coefficient of LRO is about 1.15×10 −11 (cm 2 s −1 ) and it has been shown that it can be increased by 20 % via doping strategies [5] .…”

“…However, LROs also have drawbacks such as oxygen loss, poor electrochemical kinetics, low Li-ion diffusion coefficient, and large voltage reduction, that need to be mitigated. [22][23][24][25] For example, the diffusion coefficient of LRO is about 1.15 × 10 À 11 (cm 2 s À 1 ) and it has been shown that it can be increased by 20 % via doping strategies. [5] Some investigations have highlighted the problems and have investigated coating and doping strategies.…”