adding to LCA

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aj 2020-12-23 15:22:27 +00:00
parent 495c6a58d3
commit ffaca073e3
5 changed files with 364 additions and 33 deletions

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@ -455,6 +455,28 @@
urldate = {2020-12-22}, urldate = {2020-12-22},
} }
@Misc{batt-uni-discharge-temp,
author = {{Battery University}},
howpublished = {Online},
month = mar,
title = {Discharging at High and Low Temperatures},
year = {2017},
groups = {Battery},
url = {https://batteryuniversity.com/learn/article/discharging_at_high_and_low_temperatures},
urldate = {2020-12-23},
}
@Misc{bat-uni-prolong-liion,
author = {{Battery University}},
howpublished = {Online},
month = mar,
title = {How to Prolong Lithium-based Batteries},
year = {2017},
groups = {Battery},
url = {https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries},
urldate = {2020-12-23},
}
@Comment{jabref-meta: databaseType:bibtex;} @Comment{jabref-meta: databaseType:bibtex;}
@Comment{jabref-meta: grouping: @Comment{jabref-meta: grouping:

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@ -1481,6 +1481,62 @@ Safety Circuitry
Lifespan Lifespan
\end_layout \end_layout
\begin_layout Standard
\begin_inset Float figure
wide false
sideways false
status open
\begin_layout Plain Layout
\noindent
\align center
\begin_inset Graphics
filename discharge-voltage-temperature.jpg
lyxscale 30
width 60col%
\end_inset
\end_layout
\begin_layout Plain Layout
\begin_inset Caption Standard
\begin_layout Plain Layout
Voltage-Capacity characteristics for a 18650 Li-ion cell at varying temperatures
,
\begin_inset CommandInset citation
LatexCommand citep
key "batt-uni-discharge-temp"
literal "false"
\end_inset
\begin_inset CommandInset label
LatexCommand label
name "fig:temperature-characteristics"
\end_inset
\end_layout
\end_inset
\end_layout
\begin_layout Plain Layout
\end_layout
\end_inset
\end_layout
\begin_layout Subsubsection \begin_layout Subsubsection
Financial Financial
\end_layout \end_layout
@ -1503,37 +1559,13 @@ Life-cycle Analysis
\end_layout \end_layout
\begin_layout Standard \begin_layout Standard
\begin_inset Flex TODO Note (inline) The life-cycle analysis (LCA) of Lithium-ion batteries is a complicated
status open process for a couple of reasons.
\begin_layout Plain Layout
Changing over time
\end_layout
\end_inset
\end_layout
\begin_layout Standard
\begin_inset Flex TODO Note (inline)
status open
\begin_layout Plain Layout
Meta analysis
\end_layout
\end_inset
\end_layout
\begin_layout Standard
The life-cycle analysis of Lithium-ion batteries is a complicated process
for a couple of reasons.
As repeatedly stated, Li-ion batteries have been critical to the explosion As repeatedly stated, Li-ion batteries have been critical to the explosion
of mobile consumer electronics; the development of the fabrication process of mobile consumer electronics; the development of the fabrication process
and the associated environmental effects has changed dramatically. and the associated environmental effects has changed dramatically.
More recent LCAs and meta-analyses of previous data is considered in order
to account for this.
Additionally, as a global product the values for various greenhouse gas Additionally, as a global product the values for various greenhouse gas
(GHG) and other emissions is contingent on the country within which the (GHG) and other emissions is contingent on the country within which the
cells are made. cells are made.
@ -1541,7 +1573,15 @@ The life-cycle analysis of Lithium-ion batteries is a complicated process
\begin_layout Standard \begin_layout Standard
Both the cumulative energy demand (CED) and the GHG emissions are considered. Both the cumulative energy demand (CED) and the GHG emissions are considered.
Cumulative energy demand allows Cumulative energy demand allows abstraction over the specific method of
energy production and the associated emissions.
\end_layout
\begin_layout Standard
Many of the LCA studies on Lithium-ion batteries consider a cradle-to-gate
scope without including use or end-of-life.
Two end-of-life procedures are considered as well as practices to improve
usage lifetime.
\end_layout \end_layout
\begin_layout Subsubsection \begin_layout Subsubsection
@ -1592,10 +1632,6 @@ name "fig:battery-ced-breakdown"
\end_inset \end_inset
\end_layout
\begin_layout Plain Layout
\end_layout \end_layout
\end_inset \end_inset
@ -1603,6 +1639,36 @@ name "fig:battery-ced-breakdown"
\end_layout \end_layout
\begin_layout Standard
Figure
\begin_inset CommandInset ref
LatexCommand ref
reference "fig:battery-ced-breakdown"
plural "false"
caps "false"
noprefix "false"
\end_inset
outlines the cumulative energy demand for the major elements of a Nickel/Cobalt
/Manganese cathode (NCM11) battery.
As
\begin_inset CommandInset citation
LatexCommand cite
key "circular-energy-li-lca"
literal "false"
\end_inset
points out, cathodes are tending towards a higher cathode composition of
Nickel, however the general proportions are relevant to other chemistries.
It can be seen that the production of the cells constitutes the majority
of the required CED at 75% of the total.
As this is also the element of the battery that requires periodic replacement
following degradation, a closer look at the contributing stages should
be considered.
\end_layout
\begin_layout Standard \begin_layout Standard
\begin_inset Float figure \begin_inset Float figure
wide false wide false
@ -1654,6 +1720,249 @@ name "fig:cell-ced-breakdown"
\end_layout \end_layout
\begin_layout Standard
This further breakdown can be seen in figure
\begin_inset CommandInset ref
LatexCommand ref
reference "fig:cell-ced-breakdown"
plural "false"
caps "false"
noprefix "false"
\end_inset
.
\end_layout
\begin_layout Standard
\begin_inset Float figure
wide false
sideways false
status open
\begin_layout Plain Layout
\noindent
\align center
\begin_inset Graphics
filename battery-breakdown-c02e-kwh.png
lyxscale 50
width 75col%
\end_inset
\end_layout
\begin_layout Plain Layout
\begin_inset Caption Standard
\begin_layout Plain Layout
Equivalent carbon breakdown for a NCM11 battery pack (kg CO2e/kWh),
\begin_inset CommandInset citation
LatexCommand citep
key "circular-energy-li-lca,argonne-li-ion-lca"
literal "false"
\end_inset
\begin_inset CommandInset label
LatexCommand label
name "fig:battery-co2e-breakdown"
\end_inset
\end_layout
\end_inset
\end_layout
\end_inset
\end_layout
\begin_layout Subsubsection
Use
\end_layout
\begin_layout Standard
\begin_inset Flex TODO Note (inline)
status open
\begin_layout Plain Layout
Smart charging
\end_layout
\end_inset
\end_layout
\begin_layout Standard
The use of Lithium batteries does not inherently incur a Carbon cost; the
associated cost of energy stored is accounted for by the source of this
energy, in this case ammonia fuel cells
\begin_inset Flex TODO Note (Margin)
status open
\begin_layout Plain Layout
solar panels?
\end_layout
\end_inset
.
\end_layout
\begin_layout Standard
The use of the batteries does require analysis, however.
The source and end-of-life procedures for a battery pack is a carbon intensive
operation and the ability to extend the time in-between replacement will
improve the environmental impact overall.
\end_layout
\begin_layout Standard
There are a number of ways to increase the lifespan of a battery pack.
As previously mentioned, the temperature of the cells is a key parameter
affecting both performance and lifespan,
\begin_inset CommandInset citation
LatexCommand citep
key "batt-uni-discharge-temp"
literal "false"
\end_inset
.
Although operating at a higher temperature increases performance it also
decreases lifespan.
Temperature control is already critical for safety purposes, 20°C provides
the ideal temperature for prolonging lifespan and as such will be set as
the target temperature,
\begin_inset CommandInset citation
LatexCommand citep
key "batt-uni-discharge-temp"
literal "false"
\end_inset
.
\end_layout
\begin_layout Standard
Another important aspect to the lifespan of Lithium-ion batteries is the
depth-of-discharge (DOD) which determines the number of charge cycles that
the battery will last for.
The depth-of-discharge describes the amount of capacity used each cycle
before recharging.
Lithium batteries are able to handle moderate DOD without significantly
affecting the lifespan however frequent deep discharge cycles, completely
emptying the battery, will reduce shorten it's life,
\begin_inset CommandInset citation
LatexCommand citep
key "bat-uni-prolong-liion"
literal "false"
\end_inset
.
\end_layout
\begin_layout Standard
Similar to frequently completely discharging the battery, storing a battery
fully charged for long periods of time can also shorten it's lifespan.
This can be seen presented in figure
\begin_inset CommandInset ref
LatexCommand ref
reference "fig:charge-lifespan"
plural "false"
caps "false"
noprefix "false"
\end_inset
where higher cell charge voltages can be seen to reduce capacity much faster
as time or charge cycles increases.
Also worth noting is that the capacity is initially higher for higher voltages,
it is the lifespan that can be extended by picking a more reserved value.
\end_layout
\begin_layout Standard
\begin_inset Float figure
wide false
sideways false
status open
\begin_layout Plain Layout
\noindent
\align center
\begin_inset Graphics
filename lithium-overcharge-capacity.jpg
width 70col%
\end_inset
\end_layout
\begin_layout Plain Layout
\begin_inset Caption Standard
\begin_layout Plain Layout
The lifespan of Lithium-ion cells described by the max capacity as charge
cycles increase for various charge voltages,
\begin_inset CommandInset citation
LatexCommand citep
key "bat-uni-prolong-liion"
literal "false"
\end_inset
\begin_inset CommandInset label
LatexCommand label
name "fig:charge-lifespan"
\end_inset
\end_layout
\end_inset
\end_layout
\begin_layout Plain Layout
\end_layout
\end_inset
\end_layout
\begin_layout Standard
Both of the above points, tempering DOD and charge voltage can be managed
by an intelligent charge system.
To prevent deep discharges, the charge system should instruct more ammonia
fuel cells to start up as the capacity decreases.
Additionally, it would be the system's responsibility to charge cells to
a reasonable voltage, 3.9 - 4.1 V can provide a balance between higher capacity
and longer lifespan,
\begin_inset CommandInset citation
LatexCommand citep
key "bat-uni-prolong-liion"
literal "false"
\end_inset
.
\end_layout
\begin_layout Subsubsection \begin_layout Subsubsection
End-of-Life End-of-Life
\end_layout \end_layout