Abstract: Provided are printed electrochemical cells, which utilize zinc salts for ionic transfer, and methods of fabricating such cells. In some examples, a printed electrochemical cell comprises a positive electrode with a positive current collector having a two-dimensional shape and comprising an electrolyte-facing surface formed by the graphite. For example, the positive current collector may be a graphite foil or an aluminum foil with a graphite coating. The cell also comprises electrolyte comprising an electrolyte salt and an electrolyte solvent. For example, the electrolyte salt comprises a zinc salt with a concentration of at least 30% by weight in the electrolyte. The cell is fabricated by printing a positive active material layer over the positive current collector, printing one or more electrolyte layers on various cell components, and laminating a separator layer between the positive and negative electrodes while soaking the separator layer with the electrolyte.

Abstract: In this disclosure, we describe a new chemical treatment that can be performed on lithium metal and lithium alloy surfaces to selectively remove LiH defects. This treatment utilizes an exclusive reaction between LiH and trialkyl borane to form lithium borohydride complexes, which can be easily washed away from surface using an inert organic solvent. This treatment can be useful for lithium metal and lithium alloy anodes for high energy batteries.

Abstract: In this disclosure, we describe a new chemical treatment that can be performed on lithium metal and lithium alloy surfaces to selectively remove LiH defects. This treatment utilizes an exclusive reaction between LiH and trialkyl borane to form lithium borohydride complexes, which can be easily washed away from surface using an inert organic solvent. This treatment can be useful for lithium metal and lithium alloy anodes for high energy batteries.

Abstract: A functional relation relationship has been established between SOC, nominal resistance (Rnom) and average applied load (Pavg), such that a function f(Rnom, Pavg)=SOC can be determined empirically. Load can be described using either average power or average current. The cell is tested initially to determine the relationships among these values prior to operation to create a look-up table. During operation, Rnom and Pavg can be sampled with no cell down time and can be used as input parameters with the look-up table to determine SOC accurately.

Abstract: Relaxation time constants give valuable information about a lithium polymer battery cell's state-of-charge. Moreover, determination of these time constants can be performed in real time by fitting exponential functions to transient voltage or current patterns.