An operando X-ray diffraction study of chloroaluminate anion-graphite intercalation in aluminum batteries

Abstract

We investigated rechargeable aluminum (Al) batteries composed of an Al negative electrode, a graphite positive electrode, and an ionic liquid (IL) electrolyte at temperatures down to -40 °C. The reversible battery discharge capacity at low temperatures could be superior to that at room temperature. In situ/operando electrochemical and synchrotron X-ray diffraction experiments combined with theoretical modeling revealed stable AlCl/graphite intercalation up to stage 3 at low temperatures, whereas intercalation was reversible up to stage 4 at room temperature (RT). The higher-degree anion/graphite intercalation at low temperatures affords rechargeable Al battery with higher discharge voltage (up to 2.5 V, a record for Al battery) and energy density. A remarkable cycle life of >20,000 cycles at a rate of 6C (10 minutes charge time) was achievable for Al battery operating at low temperatures, corresponding to a >50-year battery life if charged/discharged once daily.

FeSe-based superconductors with a superconducting transition temperature of 50 K

“…At last, we recall that negative ions including small inorganic ion, for example, -AlCl 4 and -ClO 4 , and large organic ion TFSI − have also been reported to be intercalated into the interlayer of 2D layered materials [43][44][45][46]. How to dope hole by intercalating such chemically inert negative ion into FeSe will help us to demonstrate a full electronic phase diagram for FeSe-based superconductors, which is very important for the construction of a universal picture for FeSe-based superconductivity.…”

The Rechargeable Aluminum Battery: Opportunities and Challenges

“…[44,56] Calculation by Gao et al [63] show that as tage-4i ntercalation reaction can contribute ac apacity of approximately 70 mAh g À1 while Jung et al [64] show that as tage-3 intercalation reaction can also occur with ac apacity of 105 mAh g À1 .T his stage-3 intercalation reaction is experimentally observed by Pan et al at at emperature below zero with ac apacity of about 100 mAh g À1 . [65] Even though no experimental evidence has been obtained to figure out the ultimate capacity of graphite in aluminumion batteries,i tc an be approximately calculated using our experience with Li-intercalated-graphite in Li-ion batteries.It is established that graphite forms aL iC 6 compound with as tage-1 Li + intercalation reaction to reach its theoretical capacity of 372 mAh g À1 .I fw et ake dimensional effects into consideration, the graphitic interlayer spacing is 0.335 nm, and the Li + radius is 0.076 nm while the radius of AlCl 4 À is 0.217 nm. Thel arger radius of AlCl 4 À leads to severe steric hindrance during intercalation so that the value of n in the C n [AlCl 4 ]c ompound must be more than the 6f or LiC 6 .…”

A Novel Moisture‐Insensitive and Low‐Corrosivity Ionic Liquid Electrolyte for Rechargeable Aluminum Batteries

“…It was also reported that, for the same EMICl–AlCl 3 electrolyte, the d i value was ≈8.95 Å, corresponding to 167% interlayer expansion upon AlCl 4 − intercalation 52. Only at a low temperature of −10 °C, at which the electrolyte decomposition was postponed and the operation potential could thus be increased to 2.5 V, intercalation of AlCl 4 − up to stage 3 was achievable 53. A stage‐4 GIC was also found for the 1‐butyl‐3‐methylimidazolium–AlCl 3 IL electrolyte at room temperature 54.…”